Express

Express is the most familiar Node.js web framework. It is a good choice when you want a large ecosystem, simple middleware composition, and conventional request/response handlers.

Choose Express When

• Your team already knows Express
• You want the largest middleware ecosystem
• You are building a traditional REST API
• You want simple req and res handler functions

Generated Entry Points

Express projects generate:

src/
  app.ts       # creates and configures the Express app
  server.ts    # starts the HTTP server

app.ts owns middleware and route mounting. server.ts owns the port and startup behavior.

Route Example

import { Router } from "express";
import { UsersController } from "./users.controller";

const router = Router();

router.get("/", UsersController.getAll);
router.post("/", UsersController.create);
router.get("/:id", UsersController.getById);
router.patch("/:id", UsersController.update);
router.delete("/:id", UsersController.remove);

export default router;

Middleware Flow

request
  |
  v
express.json()
  |
  v
optional CORS
  |
  v
API routes
  |
  v
not found middleware
  |
  v
optional error handler

Optional Features

Architecture Notes

• Minimal Express projects use route files with inline handlers.
• Modular Express projects use src/modules/{feature}.
• Layered Express projects use top-level src/routes, src/controllers, src/services, and related layer folders.