Express.js
js that provides a lightweight set of features — routing, middleware, and HTTP utilities — for building web servers and APIs.
Definition
Express.js is a minimal, unopinionated web application framework for Node.js that provides a lightweight set of features — routing, middleware, and HTTP utilities — for building web servers and APIs.
Overview
Express is one of the earliest and most influential Node.js frameworks, establishing the middleware-based request/response pipeline pattern that many later Node.js frameworks, including NestJS, build on or extend. Applications are composed from small middleware functions that process requests in sequence — parsing bodies, handling authentication, logging — with routes mapping HTTP methods and URL patterns to handler functions. Express is deliberately unopinionated about project structure, database choice, or frontend integration, leaving those decisions to the developer. It's commonly paired with databases like MongoDB, often through an ODM such as Mongoose, or with SQL databases through an ORM, and used to build REST or GraphQL APIs consumed by frontends built with React or similar frameworks. More structured, batteries-included alternatives like NestJS, or opinionated frameworks in other languages, are frequently compared against it — the fundamentals are covered directly in SkillVeris's Node.js & Express course.
Key Features
- Minimal, unopinionated core with a large ecosystem of middleware
- Middleware-based request/response pipeline
- Flexible routing for building REST APIs or full server-rendered apps
- Works with any database or ORM/ODM, commonly MongoDB with Mongoose
- Support for template engines for server-rendered HTML
- Huge community and long track record as a de facto standard Node.js framework
- Forms the foundation that later frameworks, like NestJS, build upon