API integrations that stay reliable

Integrations fail at the edges. Design for that.

Treat the other system as hostile

Timeouts, partial payloads, and duplicate events are normal. Your system should remain consistent when theirs does not.

Own the mapping

Keep a clear boundary: their IDs and fields on one side, yours on the other. Do not leak their model through your app.

Make retries idempotent

The same webhook will arrive twice. Store a key and refuse to apply the same effect again.

Log the conversation, not just the error

When money or inventory moves, you need the request, the response, and the time. That is how you debug a vendor.

Fail in a way operators can see

A queue that dies quietly is worse than a job that pages. Surface lag, dead letters, and auth expiry.