Designing integrations that fail gracefully
Retries, idempotency and dead-letter queues: the boring parts that keep system-to-system integrations honest.
Most integration outages are not caused by the happy path. Plan for the second delivery, the slow partner and the malformed message first.
Make every call safe to repeat
Give each message a stable ID and let the receiver ignore duplicates.
Decide where failures go
A dead-letter queue turns a silent loss into a ticket someone can act on.