Express.js Advanced Interview Questions
  1. Can you explain how to use the `express.Router` class to create modular, mountable route handlers? Provide an example.
  2. How can you use middleware for sub-paths or specific routes? Give an example.
  3. What is the role of the `next()` function in Express.js middleware?
  4. What is the role of the `next()` function in Express.js middleware?
  5. How can you use Express.js with a database like MongoDB?
  6. How do you secure an Express.js application? What are some practices you would follow?
  7. How can you scale an Express.js application horizontally? What practices would you follow?
  8. How do you handle file uploads in Express.js?
  9. What is the concept of Middleware chaining in Express.js?
  10. How can you ensure that your Express.js application's APIs are RESTful?
  11. How can you implement rate limiting in Express.js?
  12. How can you implement HTTPS in your Express.js application?
  13. How can you handle file uploads in Express.js?
  14. How can you ensure secure sessions in Express.js?
  15. How would you implement rate limiting in Express.js to prevent abuse of your API endpoints?
  16. How would you use clustering in Node.js to improve the performance of an Express.js application?
  17. How can you use WebSocket with Express.js to enable real-time communication?
  18. How would you implement error handling in Express.js, including both synchronous and asynchronous operations?
  19. How can you implement user authentication and session management in Express.js?
  20. How would you structure a large, scalable Express.js application? Discuss modules, routing, middleware, and error handling.
  21. What is the purpose of app.set('trust proxy', 1) in Express.js and when might you use it?
  22. What is Helmet.js and how can it be used in an Express.js application?
  23. How would you implement server-sent events in an Express.js application?
  24. How can you handle rate limiting in an Express.js application to prevent abuse?
  25. Can you explain the role of cluster module when working with an Express.js application? What advantages does it bring and what issues might you face when using it?
  26. How would you manage session persistence in an Express.js application when it's scaled out to multiple instances?
  27. How can you achieve graceful shutdown in an Express.js application to ensure ongoing requests aren't prematurely terminated when the process needs to stop?
  28. How can you implement HTTP/2 in your Express.js application?
  29. How can you use dependency injection in an Express.js application, and why might you want to do so?
  30. How can you use Express.js with TypeScript, and what benefits does it provide?
  31. How can you create a real-time application with Express.js and WebSocket, and what would be a use case for it?
  32. How can you implement a caching mechanism in Express.js to optimize response times?