Reliable Webhook Delivery for a Node.js SaaS Digest: Queues, Idempotency, and Retries

The article argues that a Node.js SaaS sending weekly digests to customers should use a durable queue, an explicit rate limiter, idempotent delivery records, and bounded exponential backoff. It notes that the common failure modes are duplicate deliveries after a crash and retry storms that ignore a receiver's rate limits. The author recommends creating a durable task with an idempotency key before any network call, so recovery has a record to inspect. Because the sender cannot know whether an ambiguous request was processed, the guarantee is typically at-least-once, requiring the receiver to honor the idempotency key. The piece also advises leasing tasks, logging each attempt, and tracking a clear state model so operators can see the full delivery timeline.