How would you ensure that the target system receives only the correct records when duplicate records are sent from the source system?

To guarantee that the target receives only unique, correct records, you should implement idempotent ingestion and deduplication logic. First, assign a unique identifier to each source record (e.g., a primary key or a hash of key fields). In the target database, enforce a unique constraint on that identifier so that any duplicate insert attempts are rejected. In the ETL pipeline, use a staging table to load incoming data, then run a deduplication step that keeps the most recent or highest‑quality record per key. You can also use change‑data‑capture (CDC) tools that emit only new or updated rows, reducing the chance of duplicates. Additionally, implement a retry mechanism that checks for existing records before inserting and logs any duplicates for audit. Finally, monitor the pipeline with metrics and alerts to detect unexpected duplicate patterns early.