How to build a reliable webhook system with queues, retries, and idempotency

A technical article on DEV Community outlines why delivering webhooks dependably is harder than it appears, particularly in payment gateway integrations where a missed POST can leave a paying customer without access. The core problem is that slow processing on the receiver's end can cause the gateway to time out and mark the delivery as failed, even if the event was eventually handled. The recommended fix is to decouple reception from processing: the endpoint immediately persists the raw payload and returns HTTP 200, while a background worker handles the heavy lifting. To prevent duplicate processing when gateways resend events, developers should enforce idempotency using a stable resource identifier and a database-level unique constraint. The article also recommends exponential backoff for retries, a dead-letter queue for persistently failing events, and detailed logging of payloads and responses to enable diagnosis and bulk reprocessing after outages.