A DEV Community article argues that webhooks are deceptively hard, acting as an unreliable, untrusted queue. Most providers promise at-least-once delivery but not ordering or uniqueness. The post details failure modes like duplicate events, out-of-order delivery, and silent drops, urging developers to design systems assuming these issues occur daily.

The proposed architecture separates ingress from business logic. A fast, stateless handler verifies signatures, persists raw payloads, and returns a 2xx acknowledgment to prevent provider retries. Raw data is stored unchanged for replay and auditability. Core principles include creating your own idempotency keys and using state transition validation to handle unordered events.

For exactly-once side effects, the article recommends a transactional outbox pattern. This involves writing a domain change and an outbox record in the same database transaction before an async worker executes external API calls. It also covers signature verification pitfalls and the necessity of observability, like traceable event IDs and dead-letter queues, to maintain system integrity.