DLQ Patterns

Concepts: paDeadLetterQueue

What They Want to Hear 'I structure DLQ events with metadata: the original event, the error message, the retry count, and the timestamp. For reprocessing, I classify errors first. Transient errors (timeout, rate limit) go back to the main topic after a delay. Permanent errors (schema mismatch, invalid data) require a code fix before replay. I never blindly replay the entire DLQ: that just reproduces the same errors and wastes compute.' This is the answer that shows you have actually dealt with a DLQ in production. Interviewers test whether you treat DLQ as a dumping ground or a first-class operational concern. Always mention monitoring (DLQ depth alerts), triage (grouping by error type), and remediation (replay tooling) as three pillars of a production DLQ strategy.