Node.js

Node.js runs JavaScript on the server. Its event-driven, non-blocking model lets one process handle many concurrent connections without a thread per request.

Where it fits

Work dominated by waiting: API layers, services that combine data from several upstream systems, real-time features and integration middleware. When a request spends most of its time waiting on a database or a third-party call, Node.js handles that pattern efficiently.

Using one language on the front and back end also lets a team share validation logic and types, and makes it easier for developers to work across the stack.

Its limits

CPU-heavy work, such as large data transformations, image processing or complex calculations, blocks the event loop and slows every other request in that process. That work can move to worker threads (the worker_threads module), to a job queue with its own worker processes, or to a separate service.

How we use it

We handle errors deliberately. Since Node.js 15, an unhandled promise rejection ends the process by default, so we run services under a process manager or orchestrator that restarts them. We also implement graceful shutdown on SIGTERM, so in-flight requests finish before the process exits, and we monitor memory use in production.

Related

System Integration & API Development, Web Application Development