System Design

Dead Letter Queues and Exponential Backoff

System Design diagram · made in Skemio

System architecture flow of an event passing to a primary consumer, failing to 1st and 2nd retry delay queues, and finally routing to a dead-letter queue.
System architecture flow of an event passing to a primary consumer, failing to 1st and 2nd retry delay queues, and finally routing to a dead-letter queue.
Open it in SkemioMake your own

What it shows

  • Immediate retries trigger cascade failures during downstream outages
  • Tiered delay queues back off from 1s to minutes with jitter
  • DLQs isolate unrecoverable poison pills for operator inspection

The takeaway

Exponential backoff delays protect downstream services, while DLQs preserve poisoned messages without blocking queues.

More system design diagrams