Webhooks Receiving Webhooks Express (with signature verification) Generic HMAC Verification Sending Webhooks Retry with Exponential Backoff Webhook Event Schema Anti-Patterns | Anti-Pattern | Fix | |--------------|-----| | No signature verification | Always verify HMAC signature | | Processing before responding 200 | Respond 200 immediately, process async | | No idempotency check | Store processed event IDs | | Using parsed body for verification | Use raw body for signature check | | No retry on send failures | Use job queue with exponential backoff | | Synchronous webhook delivery | Dispatch…