Backend Apis Interview Questions

1,054 real Backend Apis questions asked in live technical interviews — each with a model answer. Updated weekly.

🎤 Auto-captured by Assisting AI during live interviews

These Backend Apis interview questions were captured from real interviews by candidates using Assisting AI. Each links to a full model answer. For real-time help during your own interview, get Assisting AI from ₹500/day.

What are the main trade-offs of using API gateways?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses input sanitization?🟡 Medium · Conceptual · Asked 1×What is file uploads, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does CSRF protection affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×When would you choose distributed transactions in a real project?🔴 Hard · Conceptual · Asked 1×What is exponential backoff, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What is the difference between Redis Streams and WebSockets, and when would you use each?🟢 Easy · Conceptual · Asked 1×How does server-side rendering affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving background jobs?🟡 Medium · Debugging · Asked 1×How would you troubleshoot a problem involving cron jobs?🟡 Medium · Debugging · Asked 1×How would you document a production design that uses JWT?🟡 Medium · Behavioral · Asked 1×How would you design for failure recovery around cookies?🔴 Hard · System Design · Asked 1×How would you migrate an existing system to uploads safely?🔴 Hard · System Design · Asked 1×How would you troubleshoot a problem involving middleware?🟡 Medium · Debugging · Asked 1×How does HTTP headers affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you compare XSS protection and SQL injection prevention for a production system?🔴 Hard · Conceptual · Asked 1×When would you choose service-to-service authentication in a real project?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using idempotent consumers?🟡 Medium · Conceptual · Asked 1×How would you compare message queues and Kafka for a production system?🔴 Hard · Conceptual · Asked 1×How would you compare long polling and server-side rendering for a production system?🔴 Hard · Conceptual · Asked 1×How does cron jobs work at a high level?🟡 Medium · Conceptual · Asked 1×Explain the role of buffers in production systems.🟢 Easy · Conceptual · Asked 1×How would you document a production design that uses worker?🟡 Medium · Behavioral · Asked 1×How does authentication compare with a common alternative?🟡 Medium · Conceptual · Asked 1×What security considerations apply to JWT?🔴 Hard · Conceptual · Asked 1×When is cookies a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×What follow-up could reveal whether a candidate really understands CSRF?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on HTTP headers?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using ETag?🟡 Medium · Conceptual · Asked 1×When would you choose rate limiting in a real project?🟡 Medium · Conceptual · Asked 1×What is the difference between API versioning and API gateways, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you compare SQL injection prevention and service-to-service authentication for a production system?🔴 Hard · Conceptual · Asked 1×How does background jobs affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×Why is the use of NestJS important in production?🟢 Easy · Conceptual · Asked 1×How would you design for failure recovery around sessions?🔴 Hard · System Design · Asked 1×How would you explain the trade-off between correctness and performance when using file?🟢 Easy · Conceptual · Asked 1×How would you troubleshoot a problem involving uploads?🟡 Medium · Debugging · Asked 1×How does uploads compare with a common alternative?🟡 Medium · Conceptual · Asked 1×What metrics would you monitor for Node.js?🟡 Medium · Conceptual · Asked 1×What are common mistakes when using worker?🟡 Medium · Debugging · Asked 1×Describe a realistic interview scenario where buffers would be useful.🟡 Medium · Conceptual · Asked 1×Explain the role of NestJS in production systems.🟢 Easy · Conceptual · Asked 1×How would you optimize a system that depends on cookies?🟡 Medium · System Design · Asked 1×What follow-up could reveal whether a candidate really understands CORS?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using outbox pattern?🟡 Medium · Conceptual · Asked 1×How would you compare RabbitMQ and NATS for a production system?🔴 Hard · Conceptual · Asked 1×When would you choose job queues in a real project?🟡 Medium · Conceptual · Asked 1×When would you choose REST API design in a real project?🔴 Hard · Conceptual · Asked 1×How can you improve the performance of a system that uses REST API design?🔴 Hard · Conceptual · Asked 1×What is the difference between GraphQL and gRPC, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you troubleshoot a problem involving gRPC?🟡 Medium · Debugging · Asked 1×How does HTTP status codes affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How does HTTP caching work at a high level?🟡 Medium · Conceptual · Asked 1×What is cursor pagination, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How would you compare cursor pagination and rate limiting for a production system?🔴 Hard · Conceptual · Asked 1×How would you test a component that depends on rate limiting?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on API gateways?🟡 Medium · Conceptual · Asked 1×When would you choose JWT in a real project?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using JWT?🟡 Medium · Conceptual · Asked 1×What is API keys, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does API keys work at a high level?🟡 Medium · Conceptual · Asked 1×How would you compare webhooks and HMAC signatures for a production system?🔴 Hard · Conceptual · Asked 1×How would you compare HMAC signatures and request validation for a production system?🔴 Hard · Conceptual · Asked 1×When would you choose request validation in a real project?🟡 Medium · Conceptual · Asked 1×How does SQL injection prevention work at a high level?🟡 Medium · Conceptual · Asked 1×What security considerations apply to sessions?🔴 Hard · Conceptual · Asked 1×What are common mistakes when using JWT?🟡 Medium · Debugging · Asked 1×How would you implement or configure cookies in a production environment?🟡 Medium · Coding · Asked 1×What edge cases should an interviewer ask about for buffers?🟡 Medium · Conceptual · Asked 1×Which configuration choices matter most for Express?🟡 Medium · Conceptual · Asked 1×Why is the use of middleware important in production?🟢 Easy · Conceptual · Asked 1×What security considerations apply to middleware?🔴 Hard · Conceptual · Asked 1×How can you improve the performance of a system that uses timeouts?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using GraphQL?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using SOAP?🟡 Medium · Conceptual · Asked 1×When would you choose HTTP methods in a real project?🟡 Medium · Conceptual · Asked 1×When would you choose pagination in a real project?🟡 Medium · Conceptual · Asked 1×What is the difference between cursor pagination and rate limiting, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you compare rate limiting and API versioning for a production system?🔴 Hard · Conceptual · Asked 1×What is the difference between HMAC signatures and request validation, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you troubleshoot a problem involving multipart forms?🟡 Medium · Debugging · Asked 1×How can you improve the performance of a system that uses CSRF protection?🟡 Medium · Conceptual · Asked 1×How does service discovery affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you optimize a system that depends on buffers?🟡 Medium · System Design · Asked 1×How would you test a production implementation that uses JWT?🟡 Medium · Other · Asked 1×What metrics would you monitor for JWT?🟡 Medium · Conceptual · Asked 1×When is JWT a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×How should a system using CORS be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×What edge cases should an interviewer ask about for file?🟡 Medium · Conceptual · Asked 1×How would you optimize a system that depends on uploads?🟡 Medium · System Design · Asked 1×How would you troubleshoot a problem involving RabbitMQ?🟡 Medium · Debugging · Asked 1×What are common mistakes engineers make when using gRPC?🟡 Medium · Conceptual · Asked 1×What is the difference between ETag and idempotency, and when would you use each?🟢 Easy · Conceptual · Asked 1×What are common mistakes engineers make when using API versioning?🟡 Medium · Conceptual · Asked 1×When would you choose load balancers in a real project?🟡 Medium · Conceptual · Asked 1×How would you compare OAuth 2.0 and OpenID Connect for a production system?🔴 Hard · Conceptual · Asked 1×How would you troubleshoot a problem involving session management?🟡 Medium · Debugging · Asked 1×How can you improve the performance of a system that uses HTTP caching?🟡 Medium · Conceptual · Asked 1×What is load balancers, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What is webhooks, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What are common mistakes engineers make when using webhooks?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving input sanitization?🟡 Medium · Debugging · Asked 1×How does multipart forms affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you compare outbox pattern and idempotent consumers for a production system?🔴 Hard · Conceptual · Asked 1×When would you choose idempotent consumers in a real project?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using RabbitMQ?🟡 Medium · Conceptual · Asked 1×How does RabbitMQ affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving NATS?🟡 Medium · Debugging · Asked 1×What are common mistakes engineers make when using server-side rendering?🟡 Medium · Conceptual · Asked 1×Describe a realistic interview scenario where sessions would be useful.🟡 Medium · Conceptual · Asked 1×Why is the use of JWT important in production?🟢 Easy · Conceptual · Asked 1×What security considerations apply to WebSockets?🔴 Hard · Conceptual · Asked 1×Why is the use of file important in production?🟢 Easy · Conceptual · Asked 1×What are common mistakes engineers make when using HTTP headers?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses API keys?🟡 Medium · Conceptual · Asked 1×How would you compare API keys and webhooks for a production system?🔴 Hard · Conceptual · Asked 1×What are common mistakes engineers make when using SQL injection prevention?🟡 Medium · Conceptual · Asked 1×What security considerations apply to NestJS?🔴 Hard · Conceptual · Asked 1×What follow-up could reveal whether a candidate really understands sessions?🟡 Medium · Conceptual · Asked 1×Explain the role of JWT in production systems.🟢 Easy · Conceptual · Asked 1×When would you use cookies, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×What metrics would you monitor for uploads?🟡 Medium · Conceptual · Asked 1×When would you use rate, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×How does Node.js compare with a common alternative?🟡 Medium · Conceptual · Asked 1×When would you use buffers, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×What would you inspect first when buffers is slow or unstable?🟡 Medium · Debugging · Asked 1×How would you monitor and alert on failures involving buffers?🟡 Medium · Conceptual · Asked 1×What security considerations apply to clustering?🔴 Hard · Conceptual · Asked 1×Which configuration choices matter most for clustering?🟡 Medium · Conceptual · Asked 1×How does worker compare with a common alternative?🟡 Medium · Conceptual · Asked 1×How would you test a production implementation that uses Express?🟡 Medium · Other · Asked 1×How would you optimize a system that depends on Express?🟡 Medium · System Design · Asked 1×How is middleware typically used in a real system?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using pagination?🟡 Medium · Conceptual · Asked 1×What is the difference between Nginx and Apache HTTP Server, and when would you use each?🟢 Easy · Conceptual · Asked 1×How can you improve the performance of a system that uses request validation?🟡 Medium · Conceptual · Asked 1×What is the difference between file uploads and multipart forms, and when would you use each?🟢 Easy · Conceptual · Asked 1×What are common mistakes engineers make when using XSS protection?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving SQL injection prevention?🟡 Medium · Debugging · Asked 1×How does SQL injection prevention affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving feature flags?🟡 Medium · Debugging · Asked 1×When would you choose bulkheads in a real project?🟡 Medium · Conceptual · Asked 1×How does timeouts work at a high level?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses Redis Streams?🟡 Medium · Conceptual · Asked 1×How does server-side rendering work at a high level?🟡 Medium · Conceptual · Asked 1×What edge cases should an interviewer ask about for Express?🟡 Medium · Conceptual · Asked 1×How would you migrate an existing system to Express safely?🔴 Hard · System Design · Asked 1×How would you migrate an existing system to NestJS safely?🔴 Hard · System Design · Asked 1×How should a system using authentication be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×How would you monitor and alert on failures involving authentication?🟡 Medium · Conceptual · Asked 1×When would you use CSRF, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×How would you test a production implementation that uses CSRF?🟡 Medium · Other · Asked 1×What benefits and trade-offs come with WebSockets?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using HTTP methods?🟡 Medium · Conceptual · Asked 1×How would you compare HTTP methods and HTTP status codes for a production system?🔴 Hard · Conceptual · Asked 1×How does HTTP headers work at a high level?🟡 Medium · Conceptual · Asked 1×How does reverse proxies affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What is OpenID Connect, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How can you improve the performance of a system that uses microservices?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using modular monoliths?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on feature flags?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using bulkheads?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using message queues?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on Kafka?🟡 Medium · Conceptual · Asked 1×When would you choose RabbitMQ in a real project?🟡 Medium · Conceptual · Asked 1×What is the difference between background jobs and job queues, and when would you use each?🟢 Easy · Conceptual · Asked 1×What would you inspect first when authentication is slow or unstable?🟡 Medium · Debugging · Asked 1×What are common mistakes when using sessions?🟡 Medium · Debugging · Asked 1×How should a system using CSRF be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×How would you migrate an existing system to file safely?🔴 Hard · System Design · Asked 1×How would you troubleshoot a problem involving buffers?🟡 Medium · Debugging · Asked 1×How is clustering typically used in a real system?🟡 Medium · Conceptual · Asked 1×What benefits and trade-offs come with clustering?🟡 Medium · Conceptual · Asked 1×When is worker a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×Explain the role of Express in production systems.🟢 Easy · Conceptual · Asked 1×What metrics would you monitor for middleware?🟡 Medium · Conceptual · Asked 1×Explain the role of Node.js in production systems.🟢 Easy · Conceptual · Asked 1×Why is the use of clustering important in production?🟢 Easy · Conceptual · Asked 1×How would you implement or configure authentication in a production environment?🟡 Medium · Coding · Asked 1×How would you explain the trade-off between correctness and performance when using authentication?🟢 Easy · Conceptual · Asked 1×What follow-up could reveal whether a candidate really understands authentication?🟡 Medium · Conceptual · Asked 1×What edge cases should an interviewer ask about for WebSockets?🟡 Medium · Conceptual · Asked 1×Explain the role of file in production systems.🟢 Easy · Conceptual · Asked 1×What is the difference between job queues and cron jobs, and when would you use each?🟢 Easy · Conceptual · Asked 1×How does REST API design affect reliability or scalability?🔴 Hard · System Design · Asked 1×What is HTTP caching, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How would you troubleshoot a problem involving cursor pagination?🟡 Medium · Debugging · Asked 1×How would you troubleshoot a problem involving request validation?🟡 Medium · Debugging · Asked 1×What is multipart forms, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How would you monitor and alert on failures involving NestJS?🟡 Medium · Conceptual · Asked 1×How would you monitor and alert on failures involving sessions?🟡 Medium · Conceptual · Asked 1×How would you test a production implementation that uses CORS?🟡 Medium · Other · Asked 1×How is CSRF typically used in a real system?🟡 Medium · Conceptual · Asked 1×What benefits and trade-offs come with CSRF?🟡 Medium · Conceptual · Asked 1×What security considerations apply to CSRF?🔴 Hard · Conceptual · Asked 1×What edge cases should an interviewer ask about for uploads?🟡 Medium · Conceptual · Asked 1×When would you use Node.js, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×How would you explain the trade-off between correctness and performance when using buffers?🟢 Easy · Conceptual · Asked 1×What are common mistakes when using clustering?🟡 Medium · Debugging · Asked 1×How should a system using worker be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×How would you troubleshoot a problem involving circuit breakers?🟡 Medium · Debugging · Asked 1×How does bulkheads work at a high level?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using exponential backoff?🟡 Medium · Conceptual · Asked 1×How would you compare timeouts and message queues for a production system?🔴 Hard · Conceptual · Asked 1×How can you improve the performance of a system that uses NATS?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving job queues?🟡 Medium · Debugging · Asked 1×What are common mistakes engineers make when using job queues?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on HTTP methods?🟡 Medium · Conceptual · Asked 1×When would you choose HTTP caching in a real project?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using idempotency?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses file uploads?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using service discovery?🟡 Medium · Conceptual · Asked 1×How does configuration management affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you migrate an existing system to clustering safely?🔴 Hard · System Design · Asked 1×How would you test a production implementation that uses authentication?🟡 Medium · Other · Asked 1×How would you explain the trade-off between correctness and performance when using JWT?🟢 Easy · Conceptual · Asked 1×How would you document a production design that uses CSRF?🟡 Medium · Behavioral · Asked 1×How does outbox pattern work at a high level?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses idempotent consumers?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using circuit breakers?🟡 Medium · Conceptual · Asked 1×What is the difference between WebSockets and long polling, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you compare background jobs and job queues for a production system?🔴 Hard · Conceptual · Asked 1×How does idempotency work at a high level?🟡 Medium · Conceptual · Asked 1×What is the difference between reverse proxies and load balancers, and when would you use each?🟢 Easy · Conceptual · Asked 1×What are common mistakes engineers make when using Apache HTTP Server?🟡 Medium · Conceptual · Asked 1×How does HMAC signatures affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on input sanitization?🟡 Medium · Conceptual · Asked 1×How would you compare CSRF protection and XSS protection for a production system?🔴 Hard · Conceptual · Asked 1×How does GraphQL work at a high level?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses GraphQL?🟡 Medium · Conceptual · Asked 1×What is SOAP, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What is ETag, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What are the main trade-offs of using rate limiting?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses rate limiting?🟡 Medium · Conceptual · Asked 1×How does OpenID Connect affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you compare OpenID Connect and API keys for a production system?🔴 Hard · Conceptual · Asked 1×What is the difference between multipart forms and session management, and when would you use each?🟢 Easy · Conceptual · Asked 1×What is XSS protection, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What are the main trade-offs of using XSS protection?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on circuit breakers?🟡 Medium · Conceptual · Asked 1×How would you compare Kafka and RabbitMQ for a production system?🔴 Hard · Conceptual · Asked 1×What are common mistakes engineers make when using Redis Streams?🟡 Medium · Conceptual · Asked 1×How would you compare Redis Streams and WebSockets for a production system?🔴 Hard · Conceptual · Asked 1×How would you test a component that depends on long polling?🟡 Medium · Conceptual · Asked 1×How does cookies compare with a common alternative?🟡 Medium · Conceptual · Asked 1×Which configuration choices matter most for WebSockets?🟡 Medium · Conceptual · Asked 1×When would you use uploads, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×How is Node.js typically used in a real system?🟡 Medium · Conceptual · Asked 1×How would you test a production implementation that uses buffers?🟡 Medium · Other · Asked 1×Which configuration choices matter most for buffers?🟡 Medium · Conceptual · Asked 1×Explain the role of worker in production systems.🟢 Easy · Conceptual · Asked 1×How would you compare ETag and idempotency for a production system?🔴 Hard · Conceptual · Asked 1×What is JWT, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does OpenID Connect work at a high level?🟡 Medium · Conceptual · Asked 1×What is HMAC signatures, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does request validation work at a high level?🟡 Medium · Conceptual · Asked 1×How does session management affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you compare service-to-service authentication and microservices for a production system?🔴 Hard · Conceptual · Asked 1×How does distributed transactions affect reliability or scalability?🔴 Hard · Conceptual · Asked 1×What is the difference between distributed transactions and saga pattern, and when would you use each?🔴 Hard · Conceptual · Asked 1×What are the main trade-offs of using outbox pattern?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on exponential backoff?🟡 Medium · Conceptual · Asked 1×When would you choose timeouts in a real project?🟡 Medium · Conceptual · Asked 1×What is message queues, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What is the difference between Kafka and RabbitMQ, and when would you use each?🟢 Easy · Conceptual · Asked 1×What are the main trade-offs of using server-side rendering?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving server-side rendering?🟡 Medium · Debugging · Asked 1×How would you test a component that depends on job queues?🟡 Medium · Conceptual · Asked 1×What security considerations apply to authentication?🔴 Hard · Conceptual · Asked 1×What metrics would you monitor for sessions?🟡 Medium · Conceptual · Asked 1×What would you inspect first when cookies is slow or unstable?🟡 Medium · Debugging · Asked 1×Explain the role of uploads in production systems.🟢 Easy · Conceptual · Asked 1×What are common mistakes when using uploads?🟡 Medium · Debugging · Asked 1×What security considerations apply to worker?🔴 Hard · Conceptual · Asked 1×How would you optimize a system that depends on worker?🟡 Medium · System Design · Asked 1×How would you compare REST API design and GraphQL for a production system?🔴 Hard · System Design · Asked 1×How can you improve the performance of a system that uses pagination?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving OpenID Connect?🟡 Medium · Debugging · Asked 1×How would you test a component that depends on file uploads?🟡 Medium · Conceptual · Asked 1×How does CSRF protection work at a high level?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses service-to-service authentication?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving modular monoliths?🟡 Medium · Debugging · Asked 1×What is distributed transactions, and what problem does it solve?🔴 Hard · Conceptual · Asked 1×How would you troubleshoot a problem involving outbox pattern?🟡 Medium · Debugging · Asked 1×What are common mistakes engineers make when using idempotent consumers?🟡 Medium · Conceptual · Asked 1×How does bulkheads affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×When would you choose message queues in a real project?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using RabbitMQ?🟡 Medium · Conceptual · Asked 1×How does long polling affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×Which configuration choices matter most for Node.js?🟡 Medium · Conceptual · Asked 1×How should a system using buffers be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×What metrics would you monitor for cookies?🟡 Medium · Conceptual · Asked 1×Which configuration choices matter most for cookies?🟡 Medium · Conceptual · Asked 1×How would you monitor and alert on failures involving CORS?🟡 Medium · Conceptual · Asked 1×Why is the use of uploads important in production?🟢 Easy · Conceptual · Asked 1×How would you implement or configure rate in a production environment?🟡 Medium · Coding · Asked 1×How would you compare HTTP caching and ETag for a production system?🔴 Hard · Conceptual · Asked 1×When would you choose reverse proxies in a real project?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses reverse proxies?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses load balancers?🟡 Medium · Conceptual · Asked 1×When would you choose Nginx in a real project?🟡 Medium · Conceptual · Asked 1×What is the difference between webhooks and HMAC signatures, and when would you use each?🟢 Easy · Conceptual · Asked 1×How does XSS protection affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses service discovery?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using feature flags?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on retries?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using exponential backoff?🟡 Medium · Conceptual · Asked 1×What benefits and trade-offs come with NestJS?🟡 Medium · Conceptual · Asked 1×When is NestJS a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×Describe a realistic interview scenario where JWT would be useful.🟡 Medium · Conceptual · Asked 1×Why is the use of cookies important in production?🟢 Easy · Conceptual · Asked 1×How is cookies typically used in a real system?🟡 Medium · Conceptual · Asked 1×How would you document a production design that uses cookies?🟡 Medium · Behavioral · Asked 1×How does CORS compare with a common alternative?🟡 Medium · Conceptual · Asked 1×What would you inspect first when CSRF is slow or unstable?🟡 Medium · Debugging · Asked 1×How would you explain the trade-off between correctness and performance when using WebSockets?🟢 Easy · Conceptual · Asked 1×How is uploads typically used in a real system?🟡 Medium · Conceptual · Asked 1×How would you design for failure recovery around Node.js?🔴 Hard · System Design · Asked 1×Describe a realistic interview scenario where middleware would be useful.🟡 Medium · Conceptual · Asked 1×What would you inspect first when middleware is slow or unstable?🟡 Medium · Debugging · Asked 1×How would you troubleshoot a problem involving worker?🟡 Medium · Debugging · Asked 1×How does WebSockets compare with a common alternative?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using saga pattern?🟡 Medium · Conceptual · Asked 1×How does saga pattern affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What is the difference between message queues and Kafka, and when would you use each?🟢 Easy · Conceptual · Asked 1×What is the difference between server-side rendering and background jobs, and when would you use each?🟢 Easy · Conceptual · Asked 1×What is the difference between gRPC and SOAP, and when would you use each?🟢 Easy · Conceptual · Asked 1×When would you choose SOAP in a real project?🟡 Medium · Conceptual · Asked 1×How does API versioning work at a high level?🟡 Medium · Conceptual · Asked 1×What is reverse proxies, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What are the main trade-offs of using Nginx?🟡 Medium · Conceptual · Asked 1×What is OAuth 2.0, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does file uploads work at a high level?🟡 Medium · Conceptual · Asked 1×How does service-to-service authentication affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on microservices?🟡 Medium · Conceptual · Asked 1×What is feature flags, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×Describe a realistic interview scenario where uploads would be useful.🟡 Medium · Conceptual · Asked 1×How would you explain the trade-off between correctness and performance when using uploads?🟢 Easy · Conceptual · Asked 1×What follow-up could reveal whether a candidate really understands clustering?🟡 Medium · Conceptual · Asked 1×What would you inspect first when Express is slow or unstable?🟡 Medium · Debugging · Asked 1×How would you test a component that depends on distributed transactions?🔴 Hard · Conceptual · Asked 1×When would you choose gRPC in a real project?🟡 Medium · Conceptual · Asked 1×How does API gateways affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on HMAC signatures?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using request validation?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses SQL injection prevention?🟡 Medium · Conceptual · Asked 1×What is service-to-service authentication, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How would you implement or configure clustering in a production environment?🟡 Medium · Coding · Asked 1×What follow-up could reveal whether a candidate really understands worker?🟡 Medium · Conceptual · Asked 1×Describe a realistic interview scenario where authentication would be useful.🟡 Medium · Conceptual · Asked 1×Explain the role of sessions in production systems.🟢 Easy · Conceptual · Asked 1×How would you explain the trade-off between correctness and performance when using cookies?🟢 Easy · Conceptual · Asked 1×When would you choose saga pattern in a real project?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses retries?🟡 Medium · Conceptual · Asked 1×How does message queues affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×When would you choose NATS in a real project?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using Redis Streams?🟡 Medium · Conceptual · Asked 1×How does cron jobs affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses gRPC?🟡 Medium · Conceptual · Asked 1×What is the difference between SOAP and HTTP methods, and when would you use each?🟢 Easy · Conceptual · Asked 1×How does ETag work at a high level?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on ETag?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving OAuth 2.0?🟡 Medium · Debugging · Asked 1×What is session management, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does XSS protection work at a high level?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using HTTP status codes?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses Apache HTTP Server?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using CSRF protection?🟡 Medium · Conceptual · Asked 1×When would you choose XSS protection in a real project?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using microservices?🟡 Medium · Conceptual · Asked 1×What is the difference between bulkheads and retries, and when would you use each?🟢 Easy · Conceptual · Asked 1×What benefits and trade-offs come with authentication?🟡 Medium · Conceptual · Asked 1×Why is the use of CSRF important in production?🟢 Easy · Conceptual · Asked 1×How would you optimize a system that depends on file?🟡 Medium · System Design · Asked 1×What would you inspect first when rate is slow or unstable?🟡 Medium · Debugging · Asked 1×Why is the use of Node.js important in production?🟢 Easy · Conceptual · Asked 1×How would you document a production design that uses Node.js?🟡 Medium · Behavioral · Asked 1×How is Express typically used in a real system?🟡 Medium · Conceptual · Asked 1×What are common mistakes when using middleware?🟡 Medium · Debugging · Asked 1×How does pagination work at a high level?🟡 Medium · Conceptual · Asked 1×How does API keys affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How does webhooks affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you compare session management and CSRF protection for a production system?🔴 Hard · Conceptual · Asked 1×How would you test a component that depends on XSS protection?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving service-to-service authentication?🟡 Medium · Debugging · Asked 1×What are common mistakes engineers make when using service-to-service authentication?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses modular monoliths?🟡 Medium · Conceptual · Asked 1×How does exponential backoff affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How does long polling work at a high level?🟡 Medium · Conceptual · Asked 1×What edge cases should an interviewer ask about for authentication?🟡 Medium · Conceptual · Asked 1×Why is the use of sessions important in production?🟢 Easy · Conceptual · Asked 1×Describe a realistic interview scenario where CORS would be useful.🟡 Medium · Conceptual · Asked 1×How would you monitor and alert on failures involving WebSockets?🟡 Medium · Conceptual · Asked 1×Which configuration choices matter most for file?🟡 Medium · Conceptual · Asked 1×How would you explain the trade-off between correctness and performance when using rate?🟢 Easy · Conceptual · Asked 1×What would you inspect first when clustering is slow or unstable?🟡 Medium · Debugging · Asked 1×How would you test a production implementation that uses worker?🟡 Medium · Other · Asked 1×What is pagination, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What is the difference between pagination and cursor pagination, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you compare reverse proxies and load balancers for a production system?🔴 Hard · Conceptual · Asked 1×What is the difference between OpenID Connect and API keys, and when would you use each?🟢 Easy · Conceptual · Asked 1×When would you choose API keys in a real project?🟡 Medium · Conceptual · Asked 1×What is the difference between API keys and webhooks, and when would you use each?🟢 Easy · Conceptual · Asked 1×What is request validation, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What is modular monoliths, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×When would you choose feature flags in a real project?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using saga pattern?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on saga pattern?🟡 Medium · Conceptual · Asked 1×What is the difference between exponential backoff and timeouts, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you troubleshoot a problem involving Kafka?🟡 Medium · Debugging · Asked 1×How would you troubleshoot a problem involving Redis Streams?🟡 Medium · Debugging · Asked 1×How does clustering compare with a common alternative?🟡 Medium · Conceptual · Asked 1×How should a system using WebSockets be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×What would you inspect first when WebSockets is slow or unstable?🟡 Medium · Debugging · Asked 1×What would you inspect first when file is slow or unstable?🟡 Medium · Debugging · Asked 1×How would you implement or configure uploads in a production environment?🟡 Medium · Coding · Asked 1×What would you inspect first when uploads is slow or unstable?🟡 Medium · Debugging · Asked 1×What is the difference between HTTP caching and ETag, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you troubleshoot a problem involving JWT?🟡 Medium · Debugging · Asked 1×How does microservices affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What is the difference between saga pattern and outbox pattern, and when would you use each?🟢 Easy · Conceptual · Asked 1×What is outbox pattern, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What is timeouts, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does background jobs work at a high level?🟡 Medium · Conceptual · Asked 1×What follow-up could reveal whether a candidate really understands NestJS?🟡 Medium · Conceptual · Asked 1×Describe a realistic interview scenario where cookies would be useful.🟡 Medium · Conceptual · Asked 1×What are common mistakes when using Node.js?🟡 Medium · Debugging · Asked 1×What metrics would you monitor for buffers?🟡 Medium · Conceptual · Asked 1×What edge cases should an interviewer ask about for clustering?🟡 Medium · Conceptual · Asked 1×When would you use Express, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×What metrics would you monitor for clustering?🟡 Medium · Conceptual · Asked 1×What metrics would you monitor for worker?🟡 Medium · Conceptual · Asked 1×What metrics would you monitor for Express?🟡 Medium · Conceptual · Asked 1×When would you use middleware, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×How would you test a production implementation that uses middleware?🟡 Medium · Other · Asked 1×How would you document a production design that uses sessions?🟡 Medium · Behavioral · Asked 1×How does file compare with a common alternative?🟡 Medium · Conceptual · Asked 1×Why is the use of rate important in production?🟢 Easy · Conceptual · Asked 1×Describe a realistic interview scenario where rate would be useful.🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using distributed transactions?🔴 Hard · Conceptual · Asked 1×What is long polling, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does REST API design work at a high level?🔴 Hard · Conceptual · Asked 1×How does HTTP methods work at a high level?🟡 Medium · Conceptual · Asked 1×How would you compare pagination and cursor pagination for a production system?🔴 Hard · Conceptual · Asked 1×How would you test a component that depends on cursor pagination?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using reverse proxies?🟡 Medium · Conceptual · Asked 1×How would you compare file uploads and multipart forms for a production system?🔴 Hard · Conceptual · Asked 1×How can you improve the performance of a system that uses feature flags?🟡 Medium · Conceptual · Asked 1×What metrics would you monitor for CORS?🟡 Medium · Conceptual · Asked 1×Which configuration choices matter most for CSRF?🟡 Medium · Conceptual · Asked 1×How would you test a production implementation that uses rate?🟡 Medium · Other · Asked 1×What benefits and trade-offs come with Node.js?🟡 Medium · Conceptual · Asked 1×How would you optimize a system that depends on Node.js?🟡 Medium · System Design · Asked 1×What edge cases should an interviewer ask about for Node.js?🟡 Medium · Conceptual · Asked 1×How would you implement or configure buffers in a production environment?🟡 Medium · Coding · Asked 1×What follow-up could reveal whether a candidate really understands buffers?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving idempotent consumers?🟡 Medium · Debugging · Asked 1×How does idempotency affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving rate limiting?🟡 Medium · Debugging · Asked 1×How does reverse proxies work at a high level?🟡 Medium · Conceptual · Asked 1×When would you choose CSRF protection in a real project?🟡 Medium · Conceptual · Asked 1×How does configuration management work at a high level?🟡 Medium · Conceptual · Asked 1×How should a system using clustering be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×How would you explain the trade-off between correctness and performance when using sessions?🟢 Easy · Conceptual · Asked 1×How would you optimize a system that depends on JWT?🟡 Medium · System Design · Asked 1×How would you design for failure recovery around CORS?🔴 Hard · System Design · Asked 1×When would you choose outbox pattern in a real project?🟡 Medium · Conceptual · Asked 1×What is the difference between idempotent consumers and circuit breakers, and when would you use each?🟢 Easy · Conceptual · Asked 1×What is the difference between retries and exponential backoff, and when would you use each?🟢 Easy · Conceptual · Asked 1×How does pagination affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×When would you choose input sanitization in a real project?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using file uploads?🟡 Medium · Conceptual · Asked 1×How does SOAP affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×When would you choose idempotency in a real project?🟡 Medium · Conceptual · Asked 1×When would you choose API versioning in a real project?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using reverse proxies?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on request validation?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving CSRF protection?🟡 Medium · Debugging · Asked 1×How can you improve the performance of a system that uses exponential backoff?🟡 Medium · Conceptual · Asked 1×When would you choose background jobs in a real project?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on background jobs?🟡 Medium · Conceptual · Asked 1×How does job queues work at a high level?🟡 Medium · Conceptual · Asked 1×How is NestJS typically used in a real system?🟡 Medium · Conceptual · Asked 1×How should a system using NestJS be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×How would you optimize a system that depends on NestJS?🟡 Medium · System Design · Asked 1×How should a system using cookies be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×What metrics would you monitor for CSRF?🟡 Medium · Conceptual · Asked 1×How would you document a production design that uses rate?🟡 Medium · Behavioral · Asked 1×When is Node.js a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using HTTP status codes?🟡 Medium · Conceptual · Asked 1×How does ETag affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you compare Apache HTTP Server and JWT for a production system?🔴 Hard · Conceptual · Asked 1×How would you compare JWT and OAuth 2.0 for a production system?🔴 Hard · Conceptual · Asked 1×When would you choose webhooks in a real project?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving XSS protection?🟡 Medium · Debugging · Asked 1×How does microservices work at a high level?🟡 Medium · Conceptual · Asked 1×What is saga pattern, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How would you test a component that depends on idempotent consumers?🟡 Medium · Conceptual · Asked 1×What is the difference between timeouts and message queues, and when would you use each?🟢 Easy · Conceptual · Asked 1×What is NATS, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How would you troubleshoot a problem involving long polling?🟡 Medium · Debugging · Asked 1×What are the main trade-offs of using job queues?🟡 Medium · Conceptual · Asked 1×How would you test a production implementation that uses NestJS?🟡 Medium · Other · Asked 1×What would you inspect first when NestJS is slow or unstable?🟡 Medium · Debugging · Asked 1×Which configuration choices matter most for NestJS?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving authentication?🟡 Medium · Debugging · Asked 1×When would you use sessions, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×What are common mistakes when using WebSockets?🟡 Medium · Debugging · Asked 1×Why is the use of worker important in production?🟢 Easy · Conceptual · Asked 1×When would you use worker, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×Describe a realistic interview scenario where worker would be useful.🟡 Medium · Conceptual · Asked 1×What benefits and trade-offs come with middleware?🟡 Medium · Conceptual · Asked 1×How would you optimize a system that depends on middleware?🟡 Medium · System Design · Asked 1×What is HTTP status codes, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does API gateways work at a high level?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving load balancers?🟡 Medium · Debugging · Asked 1×What are the main trade-offs of using Apache HTTP Server?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using API keys?🟡 Medium · Conceptual · Asked 1×How does webhooks work at a high level?🟡 Medium · Conceptual · Asked 1×How does input sanitization work at a high level?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses multipart forms?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using CSRF protection?🟡 Medium · Conceptual · Asked 1×What is microservices, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What is the difference between modular monoliths and service discovery, and when would you use each?🟢 Easy · Conceptual · Asked 1×What are the main trade-offs of using timeouts?🟡 Medium · Conceptual · Asked 1×What would you inspect first when Node.js is slow or unstable?🟡 Medium · Debugging · Asked 1×How would you design for failure recovery around buffers?🔴 Hard · System Design · Asked 1×How would you migrate an existing system to JWT safely?🔴 Hard · System Design · Asked 1×What security considerations apply to CORS?🔴 Hard · Conceptual · Asked 1×How would you implement or configure WebSockets in a production environment?🟡 Medium · Coding · Asked 1×What metrics would you monitor for WebSockets?🟡 Medium · Conceptual · Asked 1×What follow-up could reveal whether a candidate really understands WebSockets?🟡 Medium · Conceptual · Asked 1×What benefits and trade-offs come with file?🟡 Medium · Conceptual · Asked 1×How would you test a production implementation that uses uploads?🟡 Medium · Other · Asked 1×What edge cases should an interviewer ask about for sessions?🟡 Medium · Conceptual · Asked 1×What security considerations apply to rate?🔴 Hard · Conceptual · Asked 1×How would you explain the trade-off between correctness and performance when using worker?🟢 Easy · Conceptual · Asked 1×How should a system using Express be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×When is Express a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×Explain the role of middleware in production systems.🟢 Easy · Conceptual · Asked 1×What edge cases should an interviewer ask about for NestJS?🟡 Medium · Conceptual · Asked 1×What edge cases should an interviewer ask about for JWT?🟡 Medium · Conceptual · Asked 1×How would you test a production implementation that uses cookies?🟡 Medium · Other · Asked 1×What edge cases should an interviewer ask about for CSRF?🟡 Medium · Conceptual · Asked 1×How does GraphQL affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What is HTTP headers, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How would you test a component that depends on idempotency?🟡 Medium · Conceptual · Asked 1×How does API versioning affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses JWT?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses OAuth 2.0?🟡 Medium · Conceptual · Asked 1×How does circuit breakers affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses RabbitMQ?🟡 Medium · Conceptual · Asked 1×What is the difference between RabbitMQ and NATS, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you compare NATS and Redis Streams for a production system?🔴 Hard · Conceptual · Asked 1×What is server-side rendering, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How would you test a component that depends on server-side rendering?🟡 Medium · Conceptual · Asked 1×When is middleware a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×How would you monitor and alert on failures involving cookies?🟡 Medium · Conceptual · Asked 1×What benefits and trade-offs come with Express?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using message queues?🟡 Medium · Conceptual · Asked 1×How does Redis Streams affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using GraphQL?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving HTTP methods?🟡 Medium · Debugging · Asked 1×How would you compare HTTP status codes and HTTP headers for a production system?🔴 Hard · Conceptual · Asked 1×How can you improve the performance of a system that uses HTTP headers?🟡 Medium · Conceptual · Asked 1×What is the difference between rate limiting and API versioning, and when would you use each?🟢 Easy · Conceptual · Asked 1×How can you improve the performance of a system that uses API gateways?🟡 Medium · Conceptual · Asked 1×What is Nginx, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How can you improve the performance of a system that uses webhooks?🟡 Medium · Conceptual · Asked 1×When would you choose multipart forms in a real project?🟡 Medium · Conceptual · Asked 1×How would you optimize a system that depends on authentication?🟡 Medium · System Design · Asked 1×What benefits and trade-offs come with sessions?🟡 Medium · Conceptual · Asked 1×How does distributed transactions work at a high level?🔴 Hard · Conceptual · Asked 1×How does message queues work at a high level?🟡 Medium · Conceptual · Asked 1×When would you choose long polling in a real project?🟡 Medium · Conceptual · Asked 1×What is REST API design, and what problem does it solve?🔴 Hard · Conceptual · Asked 1×How does rate limiting affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using API versioning?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using load balancers?🟡 Medium · Conceptual · Asked 1×How does Apache HTTP Server affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How does OAuth 2.0 work at a high level?🟡 Medium · Conceptual · Asked 1×How does input sanitization affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What is the difference between XSS protection and SQL injection prevention, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you compare modular monoliths and service discovery for a production system?🔴 Hard · Conceptual · Asked 1×How would you test a component that depends on configuration management?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving bulkheads?🟡 Medium · Debugging · Asked 1×How does exponential backoff work at a high level?🟡 Medium · Conceptual · Asked 1×How does Redis Streams work at a high level?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses server-side rendering?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on cron jobs?🟡 Medium · Conceptual · Asked 1×When would you choose GraphQL in a real project?🟡 Medium · Conceptual · Asked 1×What is HTTP methods, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×When would you choose API gateways in a real project?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving reverse proxies?🟡 Medium · Debugging · Asked 1×How does load balancers work at a high level?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses HMAC signatures?🟡 Medium · Conceptual · Asked 1×What is the difference between request validation and input sanitization, and when would you use each?🟢 Easy · Conceptual · Asked 1×When would you choose file uploads in a real project?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using multipart forms?🟡 Medium · Conceptual · Asked 1×When would you choose SQL injection prevention in a real project?🟡 Medium · Conceptual · Asked 1×When would you use NestJS, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×How would you implement or configure NestJS in a production environment?🟡 Medium · Coding · Asked 1×Why is the use of WebSockets important in production?🟢 Easy · Conceptual · Asked 1×What metrics would you monitor for file?🟡 Medium · Conceptual · Asked 1×How would you monitor and alert on failures involving file?🟡 Medium · Conceptual · Asked 1×Why is the use of buffers important in production?🟢 Easy · Conceptual · Asked 1×What benefits and trade-offs come with buffers?🟡 Medium · Conceptual · Asked 1×How would you optimize a system that depends on clustering?🟡 Medium · System Design · Asked 1×What edge cases should an interviewer ask about for middleware?🟡 Medium · Conceptual · Asked 1×What is idempotency, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What are the main trade-offs of using HMAC signatures?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving HMAC signatures?🟡 Medium · Debugging · Asked 1×What are common mistakes engineers make when using HMAC signatures?🟡 Medium · Conceptual · Asked 1×How would you compare multipart forms and session management for a production system?🔴 Hard · Conceptual · Asked 1×How can you improve the performance of a system that uses XSS protection?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using SQL injection prevention?🟡 Medium · Conceptual · Asked 1×When would you choose modular monoliths in a real project?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses saga pattern?🟡 Medium · Conceptual · Asked 1×When would you choose exponential backoff in a real project?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving timeouts?🟡 Medium · Debugging · Asked 1×How does NATS affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What metrics would you monitor for NestJS?🟡 Medium · Conceptual · Asked 1×How would you migrate an existing system to authentication safely?🔴 Hard · System Design · Asked 1×What follow-up could reveal whether a candidate really understands JWT?🟡 Medium · Conceptual · Asked 1×Why is the use of CORS important in production?🟢 Easy · Conceptual · Asked 1×How does CSRF compare with a common alternative?🟡 Medium · Conceptual · Asked 1×How would you monitor and alert on failures involving CSRF?🟡 Medium · Conceptual · Asked 1×How is file typically used in a real system?🟡 Medium · Conceptual · Asked 1×What edge cases should an interviewer ask about for rate?🟡 Medium · Conceptual · Asked 1×Describe a realistic interview scenario where clustering would be useful.🟡 Medium · Conceptual · Asked 1×How would you design for failure recovery around worker?🔴 Hard · System Design · Asked 1×How would you test a component that depends on gRPC?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses SOAP?🟡 Medium · Conceptual · Asked 1×When would you choose HTTP headers in a real project?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses ETag?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using idempotency?🟡 Medium · Conceptual · Asked 1×How does cursor pagination affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using load balancers?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using OpenID Connect?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using input sanitization?🟡 Medium · Conceptual · Asked 1×When would you choose Kafka in a real project?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses long polling?🟡 Medium · Conceptual · Asked 1×How does buffers compare with a common alternative?🟡 Medium · Conceptual · Asked 1×How is CORS typically used in a real system?🟡 Medium · Conceptual · Asked 1×How would you design for failure recovery around WebSockets?🔴 Hard · System Design · Asked 1×When is file a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using HTTP headers?🟡 Medium · Conceptual · Asked 1×When would you choose cursor pagination in a real project?🟡 Medium · Conceptual · Asked 1×What is the difference between API gateways and reverse proxies, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you test a component that depends on load balancers?🟡 Medium · Conceptual · Asked 1×What is the difference between JWT and OAuth 2.0, and when would you use each?🟢 Easy · Conceptual · Asked 1×What are common mistakes engineers make when using API keys?🟡 Medium · Conceptual · Asked 1×How does service-to-service authentication work at a high level?🟡 Medium · Conceptual · Asked 1×When would you choose service discovery in a real project?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using service discovery?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses configuration management?🟡 Medium · Conceptual · Asked 1×How does Kafka affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What is RabbitMQ, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How would you design for failure recovery around authentication?🔴 Hard · System Design · Asked 1×How is sessions typically used in a real system?🟡 Medium · Conceptual · Asked 1×How is JWT typically used in a real system?🟡 Medium · Conceptual · Asked 1×How would you explain the trade-off between correctness and performance when using CORS?🟢 Easy · Conceptual · Asked 1×How would you implement or configure CSRF in a production environment?🟡 Medium · Coding · Asked 1×How would you design for failure recovery around uploads?🔴 Hard · System Design · Asked 1×What security considerations apply to Node.js?🔴 Hard · Conceptual · Asked 1×What edge cases should an interviewer ask about for worker?🟡 Medium · Conceptual · Asked 1×How would you migrate an existing system to worker safely?🔴 Hard · System Design · Asked 1×Why is the use of Express important in production?🟢 Easy · Conceptual · Asked 1×How would you migrate an existing system to cookies safely?🔴 Hard · System Design · Asked 1×When would you use file, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×How does Nginx affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using session management?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving microservices?🟡 Medium · Debugging · Asked 1×What is the difference between microservices and modular monoliths, and when would you use each?🟢 Easy · Conceptual · Asked 1×How does feature flags affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving saga pattern?🟡 Medium · Debugging · Asked 1×When would you choose retries in a real project?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using retries?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using long polling?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses job queues?🟡 Medium · Conceptual · Asked 1×How should a system using sessions be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×What edge cases should an interviewer ask about for cookies?🟡 Medium · Conceptual · Asked 1×How should a system using rate be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×When is buffers a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×How is worker typically used in a real system?🟡 Medium · Conceptual · Asked 1×How would you compare server-side rendering and background jobs for a production system?🔴 Hard · Conceptual · Asked 1×How would you troubleshoot a problem involving GraphQL?🟡 Medium · Debugging · Asked 1×What are the main trade-offs of using HTTP caching?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses idempotency?🟡 Medium · Conceptual · Asked 1×How would you compare API gateways and reverse proxies for a production system?🔴 Hard · Conceptual · Asked 1×How would you test a component that depends on reverse proxies?🟡 Medium · Conceptual · Asked 1×How would you test a production implementation that uses Node.js?🟡 Medium · Other · Asked 1×How would you monitor and alert on failures involving middleware?🟡 Medium · Conceptual · Asked 1×How does sessions compare with a common alternative?🟡 Medium · Conceptual · Asked 1×What would you inspect first when sessions is slow or unstable?🟡 Medium · Debugging · Asked 1×Which configuration choices matter most for CORS?🟡 Medium · Conceptual · Asked 1×How is WebSockets typically used in a real system?🟡 Medium · Conceptual · Asked 1×How would you optimize a system that depends on WebSockets?🟡 Medium · System Design · Asked 1×When is WebSockets a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving file?🟡 Medium · Debugging · Asked 1×How can you improve the performance of a system that uses distributed transactions?🔴 Hard · Conceptual · Asked 1×What are common mistakes engineers make when using background jobs?🟡 Medium · Conceptual · Asked 1×How does gRPC affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×When would you choose Apache HTTP Server in a real project?🟡 Medium · Conceptual · Asked 1×How does JWT work at a high level?🟡 Medium · Conceptual · Asked 1×How would you compare distributed transactions and saga pattern for a production system?🔴 Hard · Conceptual · Asked 1×What is bulkheads, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How would you test a component that depends on bulkheads?🟡 Medium · Conceptual · Asked 1×How does timeouts affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using cron jobs?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on GraphQL?🟡 Medium · Conceptual · Asked 1×How does HTTP methods affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on HTTP caching?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving ETag?🟡 Medium · Debugging · Asked 1×What is API versioning, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What is API gateways, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How would you troubleshoot a problem involving Nginx?🟡 Medium · Debugging · Asked 1×What are the main trade-offs of using webhooks?🟡 Medium · Conceptual · Asked 1×How would you compare request validation and input sanitization for a production system?🔴 Hard · Conceptual · Asked 1×What are common mistakes engineers make when using multipart forms?🟡 Medium · Conceptual · Asked 1×How would you explain the trade-off between correctness and performance when using middleware?🟢 Easy · Conceptual · Asked 1×How is authentication typically used in a real system?🟡 Medium · Conceptual · Asked 1×When would you use JWT, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×What are common mistakes when using CORS?🟡 Medium · Debugging · Asked 1×How would you design for failure recovery around CSRF?🔴 Hard · System Design · Asked 1×How would you design for failure recovery around file?🔴 Hard · System Design · Asked 1×Explain the role of clustering in production systems.🟢 Easy · Conceptual · Asked 1×How would you implement or configure Express in a production environment?🟡 Medium · Coding · Asked 1×How would you implement or configure middleware in a production environment?🟡 Medium · Coding · Asked 1×What is gRPC, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How would you troubleshoot a problem involving idempotency?🟡 Medium · Debugging · Asked 1×How does load balancers affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using JWT?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving file uploads?🟡 Medium · Debugging · Asked 1×How can you improve the performance of a system that uses session management?🟡 Medium · Conceptual · Asked 1×What is SQL injection prevention, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What are the main trade-offs of using feature flags?🟡 Medium · Conceptual · Asked 1×When would you choose server-side rendering in a real project?🟡 Medium · Conceptual · Asked 1×How does job queues affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you design for failure recovery around NestJS?🔴 Hard · System Design · Asked 1×Explain the role of authentication in production systems.🟢 Easy · Conceptual · Asked 1×When would you use WebSockets, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×Explain the role of rate in production systems.🟢 Easy · Conceptual · Asked 1×What benefits and trade-offs come with rate?🟡 Medium · Conceptual · Asked 1×What is the difference between HTTP methods and HTTP status codes, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you troubleshoot a problem involving HTTP status codes?🟡 Medium · Debugging · Asked 1×How can you improve the performance of a system that uses HTTP status codes?🟡 Medium · Conceptual · Asked 1×How would you compare idempotency and pagination for a production system?🔴 Hard · Conceptual · Asked 1×How would you test a component that depends on pagination?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses cursor pagination?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using API gateways?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses Nginx?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using request validation?🟡 Medium · Conceptual · Asked 1×How does file uploads affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What is service discovery, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What are the main trade-offs of using configuration management?🟡 Medium · Conceptual · Asked 1×How would you compare configuration management and feature flags for a production system?🔴 Hard · Conceptual · Asked 1×How would you compare feature flags and distributed transactions for a production system?🔴 Hard · Conceptual · Asked 1×What are the main trade-offs of using circuit breakers?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using bulkheads?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving exponential backoff?🟡 Medium · Debugging · Asked 1×How would you test a component that depends on NATS?🟡 Medium · Conceptual · Asked 1×How would you compare job queues and cron jobs for a production system?🔴 Hard · Conceptual · Asked 1×How would you explain the trade-off between correctness and performance when using clustering?🟢 Easy · Conceptual · Asked 1×How would you monitor and alert on failures involving worker?🟡 Medium · Conceptual · Asked 1×What security considerations apply to Express?🔴 Hard · Conceptual · Asked 1×What benefits and trade-offs come with JWT?🟡 Medium · Conceptual · Asked 1×How would you implement or configure JWT in a production environment?🟡 Medium · Coding · Asked 1×How would you monitor and alert on failures involving JWT?🟡 Medium · Conceptual · Asked 1×What benefits and trade-offs come with cookies?🟡 Medium · Conceptual · Asked 1×What security considerations apply to cookies?🔴 Hard · Conceptual · Asked 1×When would you use CORS, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×How would you document a production design that uses CORS?🟡 Medium · Behavioral · Asked 1×Explain the role of CSRF in production systems.🟢 Easy · Conceptual · Asked 1×How would you implement or configure file in a production environment?🟡 Medium · Coding · Asked 1×What follow-up could reveal whether a candidate really understands uploads?🟡 Medium · Conceptual · Asked 1×How would you design for failure recovery around rate?🔴 Hard · System Design · Asked 1×Which configuration choices matter most for rate?🟡 Medium · Conceptual · Asked 1×How would you compare GraphQL and gRPC for a production system?🔴 Hard · Conceptual · Asked 1×How would you compare SOAP and HTTP methods for a production system?🔴 Hard · Conceptual · Asked 1×How does HTTP caching affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using pagination?🟡 Medium · Conceptual · Asked 1×What is rate limiting, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What is the difference between input sanitization and file uploads, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you test a component that depends on modular monoliths?🟡 Medium · Conceptual · Asked 1×How would you compare idempotent consumers and circuit breakers for a production system?🔴 Hard · Conceptual · Asked 1×What are the main trade-offs of using Kafka?🟡 Medium · Conceptual · Asked 1×What metrics would you monitor for authentication?🟡 Medium · Conceptual · Asked 1×How would you migrate an existing system to CORS safely?🔴 Hard · System Design · Asked 1×When is CSRF a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×What are common mistakes when using Express?🟡 Medium · Debugging · Asked 1×What follow-up could reveal whether a candidate really understands Express?🟡 Medium · Conceptual · Asked 1×What are common mistakes when using NestJS?🟡 Medium · Debugging · Asked 1×When would you use authentication, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×How would you optimize a system that depends on sessions?🟡 Medium · System Design · Asked 1×What follow-up could reveal whether a candidate really understands cookies?🟡 Medium · Conceptual · Asked 1×What benefits and trade-offs come with CORS?🟡 Medium · Conceptual · Asked 1×What are common mistakes when using CSRF?🟡 Medium · Debugging · Asked 1×What security considerations apply to file?🔴 Hard · Conceptual · Asked 1×What security considerations apply to uploads?🔴 Hard · Conceptual · Asked 1×What are common mistakes engineers make when using HTTP methods?🟡 Medium · Conceptual · Asked 1×What is the difference between HTTP headers and HTTP caching, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you test a component that depends on Apache HTTP Server?🟡 Medium · Conceptual · Asked 1×When would you choose OpenID Connect in a real project?🟡 Medium · Conceptual · Asked 1×How does session management work at a high level?🟡 Medium · Conceptual · Asked 1×What is the difference between service discovery and configuration management, and when would you use each?🟢 Easy · Conceptual · Asked 1×What is configuration management, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does feature flags work at a high level?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on RabbitMQ?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using cron jobs?🟡 Medium · Conceptual · Asked 1×Which configuration choices matter most for authentication?🟡 Medium · Conceptual · Asked 1×How would you implement or configure CORS in a production environment?🟡 Medium · Coding · Asked 1×What are common mistakes when using file?🟡 Medium · Debugging · Asked 1×How would you monitor and alert on failures involving uploads?🟡 Medium · Conceptual · Asked 1×How would you document a production design that uses uploads?🟡 Medium · Behavioral · Asked 1×What are common mistakes when using rate?🟡 Medium · Debugging · Asked 1×How would you monitor and alert on failures involving rate?🟡 Medium · Conceptual · Asked 1×How would you implement or configure Node.js in a production environment?🟡 Medium · Coding · Asked 1×How can you improve the performance of a system that uses Kafka?🟡 Medium · Conceptual · Asked 1×How does RabbitMQ work at a high level?🟡 Medium · Conceptual · Asked 1×What is cron jobs, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What are common mistakes engineers make when using HTTP caching?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on API versioning?🟡 Medium · Conceptual · Asked 1×How would you compare load balancers and Nginx for a production system?🔴 Hard · Conceptual · Asked 1×What are the main trade-offs of using OAuth 2.0?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on API keys?🟡 Medium · Conceptual · Asked 1×How does multipart forms work at a high level?🟡 Medium · Conceptual · Asked 1×When would you choose session management in a real project?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using session management?🟡 Medium · Conceptual · Asked 1×How would you compare microservices and modular monoliths for a production system?🔴 Hard · Conceptual · Asked 1×How would you implement or configure worker in a production environment?🟡 Medium · Coding · Asked 1×How would you test a production implementation that uses WebSockets?🟡 Medium · Other · Asked 1×How would you optimize a system that depends on rate?🟡 Medium · System Design · Asked 1×What are common mistakes engineers make when using distributed transactions?🔴 Hard · Conceptual · Asked 1×How does saga pattern work at a high level?🟡 Medium · Conceptual · Asked 1×What is the difference between circuit breakers and bulkheads, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you test a component that depends on timeouts?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses message queues?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on Redis Streams?🟡 Medium · Conceptual · Asked 1×How would you compare WebSockets and long polling for a production system?🔴 Hard · Conceptual · Asked 1×What are the main trade-offs of using long polling?🟡 Medium · Conceptual · Asked 1×When would you choose ETag in a real project?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using cursor pagination?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving API versioning?🟡 Medium · Debugging · Asked 1×What are common mistakes engineers make when using Nginx?🟡 Medium · Conceptual · Asked 1×How would you compare Nginx and Apache HTTP Server for a production system?🔴 Hard · Conceptual · Asked 1×What are common mistakes engineers make when using OAuth 2.0?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on OAuth 2.0?🟡 Medium · Conceptual · Asked 1×What is the difference between OAuth 2.0 and OpenID Connect, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you test a component that depends on session management?🟡 Medium · Conceptual · Asked 1×How does modular monoliths work at a high level?🟡 Medium · Conceptual · Asked 1×What is the difference between feature flags and distributed transactions, and when would you use each?🔴 Hard · Conceptual · Asked 1×How would you compare bulkheads and retries for a production system?🔴 Hard · Conceptual · Asked 1×How can you improve the performance of a system that uses background jobs?🟡 Medium · Conceptual · Asked 1×How would you compare gRPC and SOAP for a production system?🔴 Hard · Conceptual · Asked 1×How would you troubleshoot a problem involving HTTP headers?🟡 Medium · Debugging · Asked 1×How would you troubleshoot a problem involving pagination?🟡 Medium · Debugging · Asked 1×What are common mistakes engineers make when using rate limiting?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses API versioning?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving API gateways?🟡 Medium · Debugging · Asked 1×What is the difference between CSRF protection and XSS protection, and when would you use each?🟢 Easy · Conceptual · Asked 1×How would you compare service discovery and configuration management for a production system?🔴 Hard · Conceptual · Asked 1×Which configuration choices matter most for middleware?🟡 Medium · Conceptual · Asked 1×How should a system using JWT be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×How does JWT compare with a common alternative?🟡 Medium · Conceptual · Asked 1×What would you inspect first when JWT is slow or unstable?🟡 Medium · Debugging · Asked 1×What are common mistakes when using cookies?🟡 Medium · Debugging · Asked 1×How would you migrate an existing system to buffers safely?🔴 Hard · System Design · Asked 1×How would you document a production design that uses buffers?🟡 Medium · Behavioral · Asked 1×How would you design for failure recovery around clustering?🔴 Hard · System Design · Asked 1×How would you document a production design that uses clustering?🟡 Medium · Behavioral · Asked 1×What are common mistakes engineers make when using REST API design?🔴 Hard · Conceptual · Asked 1×What is the difference between load balancers and Nginx, and when would you use each?🟢 Easy · Conceptual · Asked 1×When would you choose OAuth 2.0 in a real project?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on OpenID Connect?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using input sanitization?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using file uploads?🟡 Medium · Conceptual · Asked 1×What is the difference between session management and CSRF protection, and when would you use each?🟢 Easy · Conceptual · Asked 1×What is CSRF protection, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does modular monoliths affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×When would you choose configuration management in a real project?🟡 Medium · Conceptual · Asked 1×How would you migrate an existing system to middleware safely?🔴 Hard · System Design · Asked 1×Describe a realistic interview scenario where CSRF would be useful.🟡 Medium · Conceptual · Asked 1×Describe a realistic interview scenario where WebSockets would be useful.🟡 Medium · Conceptual · Asked 1×How would you migrate an existing system to WebSockets safely?🔴 Hard · System Design · Asked 1×What benefits and trade-offs come with uploads?🟡 Medium · Conceptual · Asked 1×How is rate typically used in a real system?🟡 Medium · Conceptual · Asked 1×How would you migrate an existing system to Node.js safely?🔴 Hard · System Design · Asked 1×What are common mistakes when using buffers?🟡 Medium · Debugging · Asked 1×When is clustering a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×How does middleware compare with a common alternative?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using gRPC?🟡 Medium · Conceptual · Asked 1×How does cursor pagination work at a high level?🟡 Medium · Conceptual · Asked 1×How does Nginx work at a high level?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on CSRF protection?🟡 Medium · Conceptual · Asked 1×How should a system using Node.js be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×What follow-up could reveal whether a candidate really understands Node.js?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving Express?🟡 Medium · Debugging · Asked 1×What metrics would you monitor for rate?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on HTTP status codes?🟡 Medium · Conceptual · Asked 1×What is the difference between service-to-service authentication and microservices, and when would you use each?🟢 Easy · Conceptual · Asked 1×When would you choose microservices in a real project?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving service discovery?🟡 Medium · Debugging · Asked 1×What are common mistakes engineers make when using configuration management?🟡 Medium · Conceptual · Asked 1×How does outbox pattern affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How would you compare retries and exponential backoff for a production system?🔴 Hard · Conceptual · Asked 1×What is Kafka, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What are common mistakes engineers make when using Kafka?🟡 Medium · Conceptual · Asked 1×When would you choose Redis Streams in a real project?🟡 Medium · Conceptual · Asked 1×How does NestJS compare with a common alternative?🟡 Medium · Conceptual · Asked 1×How would you explain the trade-off between correctness and performance when using NestJS?🟢 Easy · Conceptual · Asked 1×How would you optimize a system that depends on CORS?🟡 Medium · System Design · Asked 1×What edge cases should an interviewer ask about for CORS?🟡 Medium · Conceptual · Asked 1×How would you migrate an existing system to CSRF safely?🔴 Hard · System Design · Asked 1×When is rate a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×How would you monitor and alert on failures involving clustering?🟡 Medium · Conceptual · Asked 1×How would you explain the trade-off between correctness and performance when using Express?🟢 Easy · Conceptual · Asked 1×How would you explain the trade-off between correctness and performance when using Node.js?🟢 Easy · Conceptual · Asked 1×How is buffers typically used in a real system?🟡 Medium · Conceptual · Asked 1×Describe a realistic interview scenario where Express would be useful.🟡 Medium · Conceptual · Asked 1×How would you design for failure recovery around Express?🔴 Hard · System Design · Asked 1×How would you implement or configure sessions in a production environment?🟡 Medium · Coding · Asked 1×How would you migrate an existing system to sessions safely?🔴 Hard · System Design · Asked 1×How would you optimize a system that depends on CSRF?🟡 Medium · System Design · Asked 1×How would you document a production design that uses file?🟡 Medium · Behavioral · Asked 1×How should a system using uploads be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×How would you test a component that depends on Nginx?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using service-to-service authentication?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on service-to-service authentication?🟡 Medium · Conceptual · Asked 1×When would you choose circuit breakers in a real project?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using NATS?🟡 Medium · Conceptual · Asked 1×How would you test a production implementation that uses sessions?🟡 Medium · Other · Asked 1×How should a system using file be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×Describe a realistic interview scenario where file would be useful.🟡 Medium · Conceptual · Asked 1×Which configuration choices matter most for uploads?🟡 Medium · Conceptual · Asked 1×When is uploads a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×What benefits and trade-offs come with worker?🟡 Medium · Conceptual · Asked 1×How would you compare saga pattern and outbox pattern for a production system?🔴 Hard · Conceptual · Asked 1×What is the difference between outbox pattern and idempotent consumers, and when would you use each?🟢 Easy · Conceptual · Asked 1×How does circuit breakers work at a high level?🟡 Medium · Conceptual · Asked 1×What is job queues, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What are the main trade-offs of using REST API design?🔴 Hard · Conceptual · Asked 1×How would you troubleshoot a problem involving REST API design?🔴 Hard · Debugging · Asked 1×How would you test a component that depends on REST API design?🔴 Hard · Conceptual · Asked 1×What is the difference between REST API design and GraphQL, and when would you use each?🔴 Hard · System Design · Asked 1×How does SOAP work at a high level?🟡 Medium · Conceptual · Asked 1×How does rate limiting work at a high level?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving Apache HTTP Server?🟡 Medium · Debugging · Asked 1×How would you compare input sanitization and file uploads for a production system?🔴 Hard · Conceptual · Asked 1×What is the difference between configuration management and feature flags, and when would you use each?🟢 Easy · Conceptual · Asked 1×Describe a realistic interview scenario where Node.js would be useful.🟡 Medium · Conceptual · Asked 1×What security considerations apply to buffers?🔴 Hard · Conceptual · Asked 1×How would you document a production design that uses Express?🟡 Medium · Behavioral · Asked 1×How should a system using middleware be designed for high load or concurrency?🔴 Hard · System Design · Asked 1×How would you document a production design that uses middleware?🟡 Medium · Behavioral · Asked 1×When is sessions a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×Explain the role of CORS in production systems.🟢 Easy · Conceptual · Asked 1×How would you document a production design that uses WebSockets?🟡 Medium · Behavioral · Asked 1×How would you test a production implementation that uses file?🟡 Medium · Other · Asked 1×How does rate compare with a common alternative?🟡 Medium · Conceptual · Asked 1×How would you migrate an existing system to rate safely?🔴 Hard · System Design · Asked 1×How would you compare circuit breakers and bulkheads for a production system?🔴 Hard · Conceptual · Asked 1×How does retries affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What are common mistakes engineers make when using timeouts?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving message queues?🟡 Medium · Debugging · Asked 1×What are common mistakes engineers make when using NATS?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using SOAP?🟡 Medium · Conceptual · Asked 1×What is the difference between idempotency and pagination, and when would you use each?🟢 Easy · Conceptual · Asked 1×How can you improve the performance of a system that uses OpenID Connect?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on webhooks?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using microservices?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on service discovery?🟡 Medium · Conceptual · Asked 1×What is retries, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does retries work at a high level?🟡 Medium · Conceptual · Asked 1×What are the main trade-offs of using retries?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on message queues?🟡 Medium · Conceptual · Asked 1×What is Redis Streams, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does HTTP status codes work at a high level?🟡 Medium · Conceptual · Asked 1×When would you choose HTTP status codes in a real project?🟡 Medium · Conceptual · Asked 1×What is the difference between HTTP status codes and HTTP headers, and when would you use each?🟢 Easy · Conceptual · Asked 1×How does Apache HTTP Server work at a high level?🟡 Medium · Conceptual · Asked 1×What is the difference between Apache HTTP Server and JWT, and when would you use each?🟢 Easy · Conceptual · Asked 1×What are the main trade-offs of using OpenID Connect?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving configuration management?🟡 Medium · Debugging · Asked 1×How would you design for failure recovery around middleware?🔴 Hard · System Design · Asked 1×How can you improve the performance of a system that uses HTTP methods?🟡 Medium · Conceptual · Asked 1×How does JWT affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How does idempotent consumers affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses bulkheads?🟡 Medium · Conceptual · Asked 1×How does Kafka work at a high level?🟡 Medium · Conceptual · Asked 1×Why is the use of authentication important in production?🟢 Easy · Conceptual · Asked 1×Explain the role of cookies in production systems.🟢 Easy · Conceptual · Asked 1×When is CORS a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×How would you monitor and alert on failures involving Node.js?🟡 Medium · Conceptual · Asked 1×How does Express compare with a common alternative?🟡 Medium · Conceptual · Asked 1×How would you compare HTTP headers and HTTP caching for a production system?🔴 Hard · Conceptual · Asked 1×What are the main trade-offs of using cursor pagination?🟡 Medium · Conceptual · Asked 1×How would you compare API versioning and API gateways for a production system?🔴 Hard · Conceptual · Asked 1×How would you troubleshoot a problem involving webhooks?🟡 Medium · Debugging · Asked 1×How would you test a component that depends on multipart forms?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on SQL injection prevention?🟡 Medium · Conceptual · Asked 1×What is the difference between SQL injection prevention and service-to-service authentication, and when would you use each?🟢 Easy · Conceptual · Asked 1×How does service discovery work at a high level?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving distributed transactions?🔴 Hard · Debugging · Asked 1×How can you improve the performance of a system that uses outbox pattern?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses circuit breakers?🟡 Medium · Conceptual · Asked 1×How would you monitor and alert on failures involving Express?🟡 Medium · Conceptual · Asked 1×When is authentication a poor choice for a production system?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving CSRF?🟡 Medium · Debugging · Asked 1×Explain the role of WebSockets in production systems.🟢 Easy · Conceptual · Asked 1×How would you troubleshoot a problem involving rate?🟡 Medium · Debugging · Asked 1×How would you troubleshoot a problem involving SOAP?🟡 Medium · Debugging · Asked 1×How would you test a component that depends on SOAP?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving HTTP caching?🟡 Medium · Debugging · Asked 1×How would you test a component that depends on outbox pattern?🟡 Medium · Conceptual · Asked 1×What is idempotent consumers, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does idempotent consumers work at a high level?🟡 Medium · Conceptual · Asked 1×What is the difference between long polling and server-side rendering, and when would you use each?🟢 Easy · Conceptual · Asked 1×What are the main trade-offs of using background jobs?🟡 Medium · Conceptual · Asked 1×Describe a realistic interview scenario where NestJS would be useful.🟡 Medium · Conceptual · Asked 1×How would you document a production design that uses authentication?🟡 Medium · Behavioral · Asked 1×Which configuration choices matter most for JWT?🟡 Medium · Conceptual · Asked 1×What would you inspect first when CORS is slow or unstable?🟡 Medium · Debugging · Asked 1×What follow-up could reveal whether a candidate really understands file?🟡 Medium · Conceptual · Asked 1×How would you test a production implementation that uses clustering?🟡 Medium · Other · Asked 1×How would you design for failure recovery around JWT?🔴 Hard · System Design · Asked 1×How would you explain the trade-off between correctness and performance when using CSRF?🟢 Easy · Conceptual · Asked 1×What are common mistakes engineers make when using ETag?🟡 Medium · Conceptual · Asked 1×How would you test a component that depends on JWT?🟡 Medium · Conceptual · Asked 1×How would you troubleshoot a problem involving API keys?🟡 Medium · Debugging · Asked 1×How does HMAC signatures work at a high level?🟡 Medium · Conceptual · Asked 1×How does request validation affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×What is circuit breakers, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How would you troubleshoot a problem involving retries?🟡 Medium · Debugging · Asked 1×How would you compare exponential backoff and timeouts for a production system?🔴 Hard · Conceptual · Asked 1×How does NATS work at a high level?🟡 Medium · Conceptual · Asked 1×What is the difference between NATS and Redis Streams, and when would you use each?🟢 Easy · Conceptual · Asked 1×What is background jobs, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What follow-up could reveal whether a candidate really understands middleware?🟡 Medium · Conceptual · Asked 1×How would you document a production design that uses NestJS?🟡 Medium · Behavioral · Asked 1×What are common mistakes when using authentication?🟡 Medium · Debugging · Asked 1×Which configuration choices matter most for sessions?🟡 Medium · Conceptual · Asked 1×When would you use clustering, and when would you choose an alternative?🟡 Medium · Conceptual · Asked 1×What would you inspect first when worker is slow or unstable?🟡 Medium · Debugging · Asked 1×Which configuration choices matter most for worker?🟡 Medium · Conceptual · Asked 1×When would you choose cron jobs in a real project?🟡 Medium · Conceptual · Asked 1×How can you improve the performance of a system that uses cron jobs?🟡 Medium · Conceptual · Asked 1×What is GraphQL, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does gRPC work at a high level?🟡 Medium · Conceptual · Asked 1×What is Apache HTTP Server, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×How does OAuth 2.0 affect reliability or scalability?🟡 Medium · Conceptual · Asked 1×When would you choose HMAC signatures in a real project?🟡 Medium · Conceptual · Asked 1×What is input sanitization, and what problem does it solve?🟢 Easy · Conceptual · Asked 1×What are common mistakes engineers make when using modular monoliths?🟡 Medium · Conceptual · Asked 1×

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