Express.js

What is Express.js?

Express.js is a minimal web framework for Node.js. It handles the parts of building a server that every application needs: routing requests to the right handler, parsing incoming data, and running a chain of functions called middleware on the way in and out. It does very little on its own, and that is the point. You assemble the rest from packages you choose.

Released in 2010 by TJ Holowaychuk, Express became the default way to write a backend in Node and stayed there for over a decade. Its middleware model, where each function can read the request, change it, and pass control to the next one, shaped how a generation of JavaScript developers think about servers. Newer frameworks like Fastify and NestJS borrow heavily from it, and NestJS even runs on top of Express by default. A typical use is a REST API where one route handles authentication, another serves user data, and a logging middleware sits in front of both.

It is unopinionated, which is freedom and rope in equal measure. Express tells you nothing about folder structure, validation, or database access. Teams that want guardrails reach for something heavier. Teams that want control reach for Express.

Express.js at Dallonses

We reach for Express when a project needs a clear, lightweight backend without a framework dictating every decision. Its middleware pattern makes auth, validation, and error handling easy to reason about, which matters when a partner inherits the code after we hand it over.

Most of our API integration work lives in this world. We build the endpoints, wire up the third-party services, and keep the surface small enough that the next engineer can read it in an afternoon. When a client comes to us with a tangle of services that need to talk to each other, Express is often the quiet layer that makes them cooperate.

Need a backend that stays readable as it grows? Let's build it.

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