Comment by codebitdaily

Idempotency is the only sustainable answer here. Whether it's at the database level using unique constraints or implementing idempotency keys in your API headers, you have to design for the 'at-least-once' delivery reality. I usually implement a 'processed_requests' table that stores the unique ID of the job. Before the worker executes any side effect (like a payment or email), it checks if that ID exists. If it does, it skips the execution and returns the previous result. It adds a bit of latency, but it's much cheaper than dealing with double-billing or corrupted data