Express.js Middleware Deep Dive

Middleware is one of the most important concepts in Express.js development.

What is Middleware?

Middleware functions execute between receiving a request and sending a response.

Common Middleware Types

Examples include:

• Authentication middleware
• Logging middleware
• Error handling middleware
• Validation middleware

Why Middleware Matters

It helps developers organize backend logic and avoid repeating code.

Best Practices

Keep middleware small, reusable, and focused on a single responsibility.

Final Thoughts

Good middleware architecture creates maintainable backend applications.