Node.js Fundamentals

  1. What is Node.js?

  2. Why should we use Node.js?

  3. How does Node.js work internally?

  4. How is Node.js different from a browser runtime?

  5. Why is Node.js single-threaded?

  6. If Node.js is single-threaded, how does it handle concurrency?

  7. What is the V8 engine?

  8. Why does Node.js use the V8 engine?

  9. What is I/O in Node.js?

  10. What is non-blocking I/O?

  11. Difference between blocking and non-blocking code

  12. Difference between synchronous and asynchronous execution

  13. What is event-driven programming?

  14. What is control flow in Node.js?

  15. What is a control flow function?

JavaScript Concepts (Node Context)

  1. What are callbacks?

  2. What is an error-first callback?

  3. What is callback hell?

  4. What are first-class functions?

  5. What is closure?

  6. What is lexical scope?

  7. What is hoisting?

  8. Difference between var, let, and const

  9. Difference between == and ===

  10. What is the global object in Node.js?

Event Loop & Async Basics

  1. What is the Event Loop?

  2. What is the role of the event queue?

  3. How does Node.js handle multiple requests concurrently?

  4. What are Promises?

  5. What problem do Promises solve?

  6. What is promise chaining?

  7. What is async/await?

  8. How does async/await improve readability?

Modules & Package Management

  1. What are modules in Node.js?

  2. What is CommonJS?

  3. What are ES Modules?

  4. Difference between CommonJS and ES Modules

  5. What is require()?

  6. How do you import a module in Node.js?

  7. Difference between exports and module.exports

  8. What is NPM?

  9. What are the main functions of NPM?

  10. What is package.json?

  11. What is node_modules?

  12. Difference between local and global package installation

  13. How do you install, update, and remove dependencies?

  14. Difference between npm and yarn

File System & Utilities

  1. What is the fs module?

  2. Difference between synchronous and asynchronous fs methods

  3. What is a Buffer?

  4. When is Buffer used?

  5. What are streams?

  6. Types of streams in Node.js

  7. Difference between readFile() and createReadStream()

  8. What is piping in Node.js?

  9. What is backpressure in streams?

Server & HTTP

  1. How do you create a simple HTTP server in Node.js?

  2. What are the different types of HTTP requests?

  3. What are Node.js API functions?

  4. How many types of API functions exist in Node.js?

  5. What is middleware?

  6. What is Express.js?

  7. Difference between Node.js and Angular

  8. Difference between frontend and backend development

  9. What is routing in Express.js?

Environment, Process & Debugging

  1. What are environment variables?

  2. How do you use process.env?

  3. What is NODE_ENV?

  4. What is REPL?

  5. What happens when you run node index.js?

  6. Difference between __dirname and process.cwd()

  7. How do you debug a Node.js application?

  8. How do you execute JavaScript code from a file?