How to Structure a Node.js Project Folder: A Practical Layout

How to Structure a Node.js Project Folder

Folder structure is a small choice with a big payoff. A clean structure keeps code findable and the codebase maintainable.

The Layout

src/
  config/
    index.js
  middlewares/
    auth.js
    error.js
    validate.js
  models/
    user.js
    connection.js
    message.js
  routes/
    auth.js
    user.js
    feed.js
    chat.js
  controllers/
    authController.js
    userController.js
    feedController.js
    chatController.js
  utils/
    db.js
    logger.js
    email.js
app.js
server.js
.env

What Each Folder Does

• config/: env vars, app-level setup, database connection.
• routes/: declares endpoints and binds them to controllers.
• controllers/: handles request/response and calls models.
• models/: Mongoose schemas and models.
• middlewares/: auth, error, validation middlewares.
• utils/: shared helpers like logger, email, db connection.

Why This Works

Separation of concerns. Routes declare endpoints; controllers handle logic; models shape data; middlewares handle cross-cutting concerns. Each file has one job.

Keep Controllers Thin

Controllers should not contain business logic. Move complex logic to a services folder if needed. Controllers parse the request, call the service, and send the response.

Keep Models Clean

Models define the schema and validation. Do not put route logic in models. Models are the data shape, not the data flow.

Single Responsibility

One file, one concern. userController.js handles user requests. It does not import from feedController.js. If two controllers share logic, move that logic to utils or services.

The Takeaway

A clean Node.js folder structure separates config, routes, controllers, models, middlewares, and utils. Each file has one job. This keeps the codebase findable and maintainable as it grows.