How to Build a Lightweight Delivery Failure Alert System Using Node.js and Lambda

A logistics team can detect delivery notification failures using two small, independently deployed programs — a Node.js metrics publisher and a separate scheduled poller, such as an AWS Lambda function. The two components share an explicit contract: for each closed time window, the poller receives an event time, delivery attempt count, and failure count. Keeping the alert evaluator in a separate deployment domain from the service it monitors prevents a rollback of either component from silently replaying old incidents or misreading stored state. The design also distinguishes between zero failures, zero attempts, and missing data, treating each as a distinct signal to avoid false assurances. This polling-based approach is recommended only when the alert surface is small, a few minutes of detection latency is acceptable, and a reliable metrics endpoint and webhook destination are already in place.