Build a Simple Monolith Backend with Node.js and TypeScript

jonl — Wed, 21 May 2025 16:51:42 +0000

A clear guide to setting up a monolithic backend using Express, TypeScript, Yarn, and modern tooling.
Build a Simple Monolith Backend with Node.js and TypeScript

Many developers jump straight into microservices, even when it's not needed. For small teams or early-stage products, a monolith is often the better choice.

This post will walk you through building a monolith backend that is easy to understand, maintain, and ready for production. We use:

Node.js + TypeScript
Express
Yarn
ESLint + Prettier
Jest for testing
Husky + Commitlint
GitHub Actions for CI

Why Monolith?

Here are a few reasons to start with a monolith:

Simpler to build and debug — everything is in one place.
Faster to develop — no need to set up multiple repos or services.
Easier to refactor later into microservices when needed.

Tools We Use

Tool	What it does
Express.js	Handles routes and middleware
TypeScript	Adds type safety and better tooling
ESLint + Prettier	Makes your code clean and consistent
Jest	For running tests
Husky + Commitlint	Ensures good commits and quality
Yarn	Dependency manager

Folder Structure

Here’s how the project is organized:

src/
├── app.ts           # Setup express and middleware
├── server.ts        # Start the server
├── routes/          # Define routes
├── controllers/     # Request handlers
├── services/        # Business logic
├── middleware/      # Error & security middleware
├── config/          # Environment setup
└── utils/           # Helper functions

Setup in 5 Steps

git clone https://github.com/jonilabss/boelpart-nodejs-monolith-ts.git
cd boelpart-nodejs-monolith-ts
yarn install
yarn dev

Your server will run at http://localhost:3000.

Running Tests

We use Jest for testing:

yarn test
yarn test:coverage

The goal is to keep test coverage as close to 100% as possible.

Git & CI Workflow

We use Husky, Lint-Staged, and Commitlint to make sure every commit is clean.

Only allow commits that follow Conventional Commits
Lint and test before commit and push
CI with GitHub Actions runs on every pull request

CI config is in .github/workflows/ci.yml.

Deployment

You can deploy this project on:

Railway, Render, Vercel (for serverless)
Docker
PM2 (on your own VPS)

To build and start:

yarn build
yarn start

Final Thoughts

Monoliths are still useful, especially if you use the right tools. This setup gives you a strong foundation and makes it easier to move to microservices in the future if needed.

References

Want examples like login features, global error handlers, or DB integration (MongoDB, PostgreSQL)?
Check out the GitHub repo.

DEV Community: jonl