Node.js

Node.js is the environment that made it possible to write JavaScript outside the browser, on the server. Thanks to Chrome's V8 engine, it runs the same language on both server and front end, which helped make JavaScript the most widely used language on the modern web.

What is Node.js used for?

Node.js powers web servers, APIs, command-line tools, and the entire front-end build chain (bundlers, compilers). Its non-blocking model handles a large number of simultaneous connections with few resources, ideal for real-time APIs. It's the foundation frameworks like Next.js build on, along with the npm ecosystem, the largest package registry in the world.

Node.js or another runtime?

Against newer runtimes like Deno or Bun, Node.js remains the standard thanks to its maturity, stability, and the sheer size of its npm ecosystem. Bun starts faster, but Node.js keeps the compatibility and production trust that comes with age. It containerizes natively with Docker.

What are the limits of Node.js?

The single-threaded model doesn't handle CPU-heavy computation well, since it blocks the event loop. npm dependency trees can balloon quickly and raise security concerns. For intensive computation, languages like Rust or Go are a better fit.