Node.js interview questions and answers


Node.js is an open-source, single-threaded, cross-platform, JavaScript run-time environment that executes JavaScript on the server end.

Node.js is becoming very popular on server-side applications. Following are some useful interview questions about Node.js.

What does the runtime environment mean in Node.js?
What is Node.js?
What is Node.js Process Model?
What are the data types in Node.js?
How to create a simple server in Node.js that returns Hello World?
How do Node.js works?
What is an error-first callback?
What is callback hell in Node.js?
What are Promises in Node.js?
What tools can be used to assure consistent style?
When should you npm and when yarn?
What is a stub?
What is a test pyramid? How can you implement it when talking about HTTP APIs?
How can you secure your HTTP cookies against XSS attacks?
How can you make sure your dependencies are safe?
What is Event loop in Node.js? How does it work?
What is REPL? What purpose it is used for?
What is the difference between Asynchronous and Non-blocking?
How to debug an application in Node.js?
What are some of the most popular packages of Node.js?
What is EventEmitter in Node.js?
How many types of streams are present in node.js?
What is crypto in Node.js? How do you cipher the secure information in Node.js?
What is the use of DNS module in Node.js?
What are the security mechanisms available in Node.js?
Name the types of API functions in Node.js.
How does Node.js handle child threads?
What is the preferred method of resolving unhandled exceptions in Node.js?
How does Node.js support multi-processor platforms, and does it fully utilize all processor resources?
What is typically the first argument passed to a Node.js callback handler?
How Node.js read the content of a file?
What is JIT and how is it related to Node.js?
What is difference between put and patch?
List types of Http requests supported by Node.js.
Why to use Express.js?
Write the steps for setting up an Express JS application.
Since node is a single threaded process, how to make use of all CPUs?
What does emitter do and what is dispatcher?
How to kill child processes that spawn their own child processes in Node.js?
What do you understand by Reactor Pattern in Node.js?
What are the key features of Node.js?
What are globals in Node.js?
What is chaining process in Node.js?
What is a control flow function? what are the steps does it execute?
What is npm in Node.js?
When to use Node.js and when not to use it?
Explain how does Node.js work?
Is Node.js entirely based on a single-thread?
How to make post request in Node.js?
Can you create http server in Node.js, explain the code used for it?
How to load html in Node.js?
How can you listen on port 80 with Node?
What is the difference between operational and programmer errors?
Why npm shrinkwrap is useful?
What is your favourite HTTP framework and why?
What are the Challenges with Node.js?
What is the difference between Node.js vs Ajax?
How Node.js overcomes the problem of blocking of I/O operations?
Mention the steps by which you can async in Node.js?
What are the timing features of Node.js?
What is LTS releases of Node.js why should you care?
Why should you separate Express ‘app’ and ‘server’?
What is the difference between process.nextTick() and setImmediate()?
What is difference between JavaScript and Node.js?
What are the difference between Events and Callbacks?
Explain RESTful Web Services in Node.js?
How to handle file upload in Node js?
Explain the terms body-parser, cookie-parser, debug, jade, morgan, nodemon, pm2, serve-favicon, cors in Express JS?
How does routing work in Node.js
How Node prevents blocking code?
What is difference between promise and async await in node js?
How to use JSON Web Token (JWT) for authentication in node js?
How to build a microservices architecture with node js?
How to use Q promise in node js?
How to use locale (i18n) in node js?
How to Implement Memcached in Nodejs?
Explain Error Handling approaches in Nodejs?
How to generate and verify checksum of the given string in Nodejs
What is Callback function in node.js?
What is asynchronous programming in node.js?