Building Reliable Webhook Delivery: Retries, Signatures, and Failure Handling

Building Reliable Webhook Delivery: Retries, Signatures, and Failure Handling Your webhook fires. The receiver is down. The event is lost forever. The Problem With Fire-and-Forget Most webhook implementations: serialize payload, POST to URL, move on. If the receiver returns 500 or times out, the event vanishes. No retry. No record. No way to recover. Webhook Architecture Event -> Queue -> Delivery Worker -> HTTP POST -> Receiver | (on failure) Retry Queue -> Exponential Backoff -> DLQ Store every event in a database. The delivery worker reads from the queue and attempts delivery. On failure, schedule a retry with exponential backoff. Signing Webhooks Never trust the sender without verification. Sign every payload with HMAC-SHA256: import crypto from "crypto"; function signPayload(payload: string, secret: string): string { return crypto.createHmac("sha256", secret).update(payload).digest("hex"); } function verifyWebhook(payload: string, signature: string, secret: strin