Top 32 Node js Interview Questions 2023

Through “Libuv”, Node.js gets access to the multi-threading capabilities of the underlying operating system. This process can return a response only after the file is pushed into the buffer completely, moreover, the process must read the file fully. It stores documents using the “BSON” format, which means “Binary JSON”. Node.js works very well with databases like MongoDB, which is a key advantage of this runtime environment. Describe the projects you have and how the contribution of the Node.js developer will help your organization. Explain whether you have development projects, maintenance projects, or both.

• This means that setImmediate() has a higher priority than setTimeout().
• Try your best to prove your knowledge on instance creation, class methods and static methods.
• The program is designed to simulate real, everyday JavaScript scenarios that your developer applicants are likely to encounter in their work.
• Node.js is single-threaded, which means that it can only execute one task at a time.
• These tests should focus on testing the functionality of the endpoint in isolation without making any external requests or dependencies.
• Finally, separating your app and server can make it easier to switch to a different server if necessary.
• NaN and Infinity are two special values that can be the result of operations that normally return numbers.

Cluster is a process to handle thread execution load while working with multi-core systems. In order to check for the proper working of the code, we need to verify error-free execution. In this regard, error-first callbacks are used, which will send error first, followed by related data to the error. Non-blocking operations in Node Js are carried out with the help of the event loop.

How does Node.js overcome the problem of blocking I/O operations?

They can ask them to solve coding challenges and provide them with a coding task to get a more well-rounded understanding of the candidate’s abilities and skills. Also known as self-invoking (or self-executing) functions, those functions are, as the name states, immediately executed as soon as they are defined. Another aspect is that they create a namespace which cannot be reached outside which prevents the pollution of the global environment. As the JavaScript is a prototype based language, you will be directed with inheritance related questions. While answering them, try to emphasize on classical inheritance and prototypal inheritance where JavaScript can simulate them both. Be prepared with constructors, new operator and the ES6 class implementation.

If you study the questions and answers presented in this guide, you should get a pretty good idea of ​​what you can expect from the candidate. Event Emitter is a special module that smooths the path of communication between objects in NODE.js. It is at the core of asynchronous event-driven architecture of NODE. An event emitter is a pattern that listens to a named event, fires a node.js callback, then emits that event with a value.

Junior Angular Developer JavaScript

Node.js is great for some applications but can introduce significant problems in the wrong context. To address these shortcomings, developers create and use various frameworks. Although this list is long and ever-changing, you should know at least half a dozen popular frameworks and what they offer. Now that we’ve covered some of the popular Node.JS beginner interview questions, https://wizardsdev.com/en/vacancy/junior-node-js-developer/ let’s move on to the advanced Node.JS interview questions and answers for experienced web developers. Developer candidates often dislike traditional coding tests, because they have to remember algorithms they simply don’t use in their everyday work. DevSkiller testing is different and developers appreciate the chance to use normal coding tools and conventions.

Your employee is no longer a beginner but an experienced developer who knows the subtleties and accurately identifies the system’s advantages and disadvantages. In this section, not theoretical Node.js expert interview questions but practical issues related to coding and solving complex problems are already critical. With answers to advanced Node.js interview questions, you will have a complete picture of your employee and their appropriate experience for that level. It is possible to make hiring Node.js specialists understandable and almost effortless. That is why we have prepared Node.js interview questions and answers for experienced candidates and beginners to make an employer’s life much easier. In our article, you can see the questions for the junior, middle, and senior Node.js developers to get acquainted with soft skills questions, which help to get to know the candidate.

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This means that setImmediate() has a higher priority than setTimeout(). Worker threads and clusters are two different approaches to leveraging the power of multiple CPUs in Node.js. While clusters create multiple instances of a Node.js process, each running on a separate CPU core, worker threads provide a way to create multiple threads within a single process. Front-end developers focus on the client side of the application, while back-end developers focus on the server side of the application.

The program is designed to simulate real, everyday JavaScript scenarios that your developer applicants are likely to encounter in their work. This method of testing allows recruiters to have a comprehensive understanding of an applicant’s skill level from the very beginning of the screening process. Meaning you can accurately test exactly how well each applicant will perform on the job, during the screening process. This method allows you to accurately assess a JavaScript developer’s time-management skills, problem-solving ability, and JavaScript coding skills- all before the interview stage. Whenever an event gets fired, its listener function starts executing.

List down the major benefits of using Node.js?

Spawn() launches a new process with the available set of commands. NPM stands for Node Package Manager, responsible for managing all the packages and modules for Node.js. A web server using Node.js typically has a workflow that is quite similar to the diagram illustrated below.

The Node.js provides Buffer class to store raw data similar to an array of integers but corresponds to a raw memory allocation outside the V8 heap. It is a global class and can be accessed in an application without importing a buffer module. Buffer class is used because pure JavaScript is not compatible with binary data. So, when dealing with TCP streams or the file system, it’s necessary to handle octet streams. The above Node.js interview questions should help you effectively screen candidates at any upcoming Node.js interviews you may hold.

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Not only is this more convenient for the candidates, but it will save your business countless hours and money spent on in-house testing. A recruiter only needs to do is send out a JavaScript test invite and the candidates can get started wherever they are. It is used to supplement Node.js asynchronous I/O functionality. The Libuv library maintains a thread pool that is used to carry out lengthy activities in the background without pausing the program’s main thread. A buffer is a type of memory typically employed by streams to temporarily store data before its consumption. When memory is allocated outside of the V8 JavaScript engine, that space is represented as a buffer.

In Node.js, the fs module provides methods for working with the file system. Stat() method returns an object that contains information about the file, such as the file size, creation date, and modified date. The crypto module is widely used in Node.js applications to generate secure random numbers, create digital signatures, and verify signatures. It also provides support for various encryption algorithms such as AES, DES, and RSA. Global objects in Node.js are objects that are available in all modules without the need for an explicit require statement.