Node.js and Express remain the go-to stack for building RESTful APIs that are both fast and scalable. In this post, we’ll cover:

1. Project Structure & Modularity
- Organizing controllers, routes, and middlewares for maintainability.
- Using environment variables and configuration files.

2. Database Integration
- Connecting to MongoDB with Mongoose vs. PostgreSQL with Sequelize.
- Designing schemas and handling migrations.

3. Performance Optimization
- Implementing clustering with the Node.js cluster module.
- Using caching layers (Redis) to offload frequent queries.

4. Security Essentials
- Protecting routes with JWT authentication.
- Validating and sanitizing input with libraries like Joi or Zod.

5. Testing & CI/CD
- Writing unit and integration tests with Jest and Supertest.
- Automating deployments on platforms like Heroku or DigitalOcean.

Practical code snippets and real-world tips will help you ship production-ready APIs that handle thousands of requests per second with ease.