Node js Interview Questions and Answers in 2023

In contrast, backend developers focus on processes running in the background – something that customers don’t see. They are also responsible for the functionality of the site, simply from a broader perspective. One of the more subjective interview questions about Node JS. The candidate should express their opinion about the tool and its benefits. Since there are quite a few of them, most likely the candidate will describe those that interest them or bring them the greatest benefit. Get a printable version of all questions and answers & bring it as a cheat sheet to your next interview. Node.js is a runtime environment for JavaScript applications, however, Angular.js is an open-source web application framework to develop web applications.

Doing this will ensure every candidate you invite to the interview stage fully understands Node.js. Ask your candidates some of these Node.js interview questions about skills and abilities to evaluate their technical and non-technical knowledge. Ask your mid-level applicants some of these 14 intermediate Node.js interview questions during an interview to test their expertise and experience. Finding the ideal list of questions is difficult, but we’ve made this step easier. Check out this article’s 100 Node.js interview questions to hire a professional Node.js programmer for your business. The best approach to applicant evaluation is to combine skills assessments that include a Node.js test with interviews in which you ask candidates Node.js interview questions.

Node.js Interview Questions for Freshers

They will also be able to explain what these modules do and how they work. For example, the stream module handles streaming data, and the HTTP module helps developers make a Node.js HTTP server. Here are five sample answers to some of the most important beginner Node.js interview questions. Check these answers when reviewing your applicants’ responses. They either return the result of execution or the error/exception. Implementing promises requires the use of function which waits for the promise object to return.

• Let AI take all your interview notes and write human-level candidate summaries automically.
• Whether you are coming up with a top-notch scalable app or a basic application, hiring a developer depends on your needs.
• A function is called an asynchronous function when some external activity must complete before processing a result.
• This communication between the two nodes makes use of all CPUs.
• Refer to these answers to evaluate the depth of your candidates‘ responses.
• The event loop is the processing model’s beating heart in Node.js.

Node.js is a JavaScript runtime environment built with Chrome’s V8 JavaScript engine as a platform. It’s popular because it’s lightweight and efficient, due to its event-driven and non-blocking I/O model. Built with performance as its primary focus, Node.js processes the JavaScript code into the native machine code, which your computer can use to execute processes. Node.js is a JavaScript environment used to execute JavaScript code outside the browser. The cluster module in Node Js enables developers to create multiple processes or threads that can be used to take advantage of multiple CPU cores.

What is an event loop in Node.js?

The “process.nextTick()” function waits for the execution of an action. This process invokes the callback function only after the event loop completes. All objects that emit events are parts of the “EventEmitter” class. “EventEmitter objects” emit events, and all of the functions attached to that event are called synchronously. Events that are emitted by event emitters have to listen in order to continue the asynchronous execution of the threads.

Node uses “libuv” to handle its IO in a platform-agnostic way. On windows, it uses completion ports for unix it uses epoll or kqueue etc. So, it makes a non-blocking request and upon a request, it queues it within the event loop which call the JavaScript ‘callback’ on the main JavaScript thread.

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The difference between a cluster module and a load balancer is that instead of distributing load between processes, the balancer distributes requests. This will pause the async function and wait for the Promise to resolve prior to moving on. If the function throws an error, https://wizardsdev.com/en/vacancy/junior-node-js-developer/ the Promise will be rejected. If the function returns a value, the Promise will be resolved. Moreover, Node.js has an optimized design which utilizes both JavaScript and C++ to guarantee maximum performance. JavaScript executes at the server-side by Google Chrome v8 engine.

NoSQL databases are known for their flexibility, scalability, and performance. When answering this question, don’t just give a general overview of the box model. Instead, discuss the different components and how they interact with one another. Feel free to use real-world examples or mention any challenges you’ve faced related to the box model to demonstrate your experience and problem-solving skills.

Looking for Node.js Developers?

It gives information to the npm through which npm identifies a project and its dependencies. Apart from this, it contains other metadata like project description, version, license information, and configuration data. Asynchronous or non-synchronous means that we will not receive a response to a message immediately — there is no dependency or order of execution. The server stores information and acknowledges when the action is performed. The fork() method in Node Js creates a new process that is a copy of the existing one.

Look out for applicants who can give a few examples of events, such as the click of a mouse or the pressing of a key on the keyboard. Since Node.js developers must work with many clients, they require several key soft skills. Some of the top soft skills included in job postings for software developers are communication, teamwork, problem-solving, and planning.

By performing these tasks asynchronously, Node.js can handle a large number of concurrent requests without blocking the event loop. A Full stack Javascript Developer (React.js + Node.js) is a software engineer who specializes in using the Javascript programming language to develop web applications. They are responsible for the entire development process, from front-end to back-end. In addition, they should be able to use various tools and libraries, such as Webpack, Babel, and React Router. Single Threaded but highly Scalable – Node.js uses a single threaded model with event looping.

Show me how you gathered information, assessed options, and made your final decision. Also, mention how you moved forward after your decision and what you’ve learned from that experience. Remember, it’s all about showcasing your skills and thought process, not necessarily the outcome itself.