Node.js design avoids duplicate notifications in e-commerce shipment updates using idempotency

A Node.js technical article outlines a system for handling e-commerce shipment notifications. It describes a multi-step process triggered by a cron job that calls a public HTTPS endpoint to enqueue subscriber delivery jobs. The design uses unique idempotency keys for each delivery to prevent duplicates from multiple retry mechanisms. The architecture emphasizes separating scheduling logic from processing to ensure reliable, rate-limited notifications.