Commonly Asked Node.Js Interview Questions

Technology is advancing and today newer and advanced platforms with unique selling points are becoming popular. One such recent development is the node js tool. Node.js is a development platform that is aimed at building server-side applications. 

It uses its own web server for better control. As the popularity of the platform increases, we are seeing that more job opportunities are opening and the need for experienced and advanced workforce in this segment is the need of the hour.  To better summarize it node js is:

1. Node.js is a server framework, and is free
2. It runs on Windows, Linux, Mac OS, and so on
3. Node.js utilizes JavaScript on the server

Characteristics of Node js 

• Google Chrome V8 JavaScript Engine
• Modules/Packages
• Event Driven, Single-Threaded I/O Model

Node js comes with a host of advantages dues to its unique features, some of the reasons why you should use Node js are as follows:

• Single free codebase
• Wide range of hosting options
• JavaScript is the longest running language, 99% of developers know some of it
• Good for data streaming, thus for audio and video files, as example
• Ability to keep data in native JSON (object notation) format in your database
• It is fast, due to Google innovative technologies and the event loop
• Modern Architecture and Scalability 
• Faster Time to Market 

With technological driven changes happening all around us it is important to understand what the uses of different developing platforms and where they will be used bet. Some of the uses of Node js are to 

1. Stream data
2. Chats / RTAs
3. Web applications
4. Single page apps
5. Proxy
6. Dashboards

Scope and roles for a Node js Developer:

This is a technology that is gaining momentum and we are seeing a demand for Node.js developers in the coming future. If you are thinking of a career in Node.js , then it is important to understand the responsibility of what you will be doing :

• Perform diagnostic tests, fix bugs, and provide technical support to users 
• Document software development processes and prepare project reports
• Provide suggestions for improvement and apply them to daily tasks and processes 
• Write clean, efficient, and reusable code
• Develop and manage server-side components   
• Design and deploy high-performance applications
• Ensure that the main database and front-end requests are at their optimal performance
• Identify and implement data storage solutions
• Integrate server-side logic to the user-facing components built by front-end developers 
• Incorporate data protection and cybersecurity measures

As the popularity for Node.js grows, lets try to understand what sort of Node.js interview questions can be expected.  We will cover basic interview questions, interview questions for freshers , and interview questions for experienced developers. 

The below questions are designed  for you to understand what kind of interview questions can be expected and includes a few tricky questions to help you prepare better. 

Basic interview questions for Node.js 

If you are a fresher or someone who is new to this profile, then preparing for interview questions on node js is priority. They are going to be basic and simple to know if you understand node js. They will want to test your fundamentals and how strong you are with the foundation of node js. 

Remember while preparing for Node.js interview questions you can use technical terms and jargons, but do not go overboard with it. 

1. Explain Node.js and its uses?
2. Why would one use Node.js?
3. Explain Node.js working?
4. Why is Node.js Single-threaded?
5. What is Node.js callback?
6. What is I/O? 
7. Explain Node.js uses?
8. What are the backend and frontend development differences? 
9. What is NPM?
10. What are the modules in Node.js?
11. With backend technologies like PHP or Java, why the preference for Node.js?
12. What difference are present between Node.js and Angular?
13. Name the database used typically with Node.js?
14. What are Node js’s popularly used libraries?
15. What are Node.js advantages and disadvantages?
16. What command is required for external libraries to be imported?

Intermediate interview questions for Node.js 

At this stage you have use node js., to develop applications and add value to the business. You are either looking to change your career profile or are interviewing for the next level. You will be grilled on your knowledge, how you used it to create and develop software.  

You might be given a case study to solve, so it better to prepare yourselves, by brushing up your knowledge and understand what questions can be asked. Citing real time use of node js will help your interview process. 

1. What is the framework that is used majorly in Node.js today?
2. What are the security implementations that are present in Node.j
3. What is the meaning of a test pyramid?
4. What is Libuv?
5. What is the difference between spawn and fork methods in Node.js?
6. Why does Google use the V8 engine for Node.js?
7. What is the use of middleware in Node.js?
8. Explain the meaning of event-driven programming?
9. Explain the Node.js Event Loop?
10. Explain the EventEmitter function in Node.js?
11. Explain the kinds of Node.js API functions?
12. Explain the operation of the file package.json?
13. How does the URL module work in Node.js?
14. Explain what is meant by the packaged Express.js?
15. How does one create a simple application in Express.js?
16. Explain Node.js streams?
17. When working with dependency, how is it updated, installed and deleted?
18. To return the expression Hello World, create a simple Node.js server?
19. What is meant by non-blocking and asynchronous Node.js APIs?
20. Explain the implementation of Noe.js’s async?
21. Explain what is meant by module.exports and their purpose?
22. Explain the Node.js callback function?

Advanced interview questions for Node.js 

If you are interviewing for a higher position , you have already worked with node js application for sometime, the interview questions will be designed to check you knowledge, how well versed are you do you have a in-depth thorough understand and what and how are you going to use node js to bring to the table creative and efficient solutions to problems.

1. Explain Node.js’s REPL functioning?
2. Explain what is meant by the control flow function?
3. How are function calls managed by the control flow function?
4. Explain the differences between spawn and fork methods in Node.js?
5. Explain the Node.js buffer class?
6. What is Node.js piping?
7. How does one flag the files read/write operations?
8. Explain file opening in Node.js?
9. What is called the callback hell in Node.js?
10. Explain the Node.js reactor pattern?
11. What is the Node.js test pyramid?
12. Explain exit codes in Node.js?
13. What is the Node.js concept about middleware?
14. Explain the different kinds of HTTP requests?
15. How does one connect Node.js to a MongoDB database?
16. Explain what is NODE_ENV and its purpose?
17. Explain the various kinds of timing features in Node.js?
18. What is the use of the crypto module in Node.js?
19.  What is a passport in Node.js?
20. How to get information about a file in Node.js?
21. Why do you think you are the right fit for this Node.js role?
22. What is the use of module.exports in Node.js?

Be its basic, intermediate or advanced level questions for an interview for node js . it is important to brush up on these skills, in order to do that you can access our online courses that will assist you, help you understand in detail and depth of how to prepare , what to prepare and what to do to enhance your career and take it in the right direction. Apart from the above questions you will also have to have the following additional soft skills to give you an edge over the others:

1. Soft skills 
2. Time management and organizational skill
3. Strong analytical competencies
4. Effective communication skills 
5. Willingness to learn

Learning is an ongoing process and it never stops, same as evolution. If you do not keep up, you will be left behind and become obsolete. Node.js is an up-and-coming technology and the demand for developers in this segment is growing at a steady pace. 

If you are going to be sitting for an interview you need to brush up, understand and be able to crack the interview. You need a comprehensive understanding of what node js is and what kind of node js question you will be asked. 

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The comprehensive program trains you on building full stack web and mobile applications end-to-end using the MERN stack, which includes Node.js. With over 70+ live sessions with faculty from the industry, you learn with hands-on training through assignments, mini-projects, and a capstone project.

The best way to prepare for a Node.js interview is going through all the questions above and preparing your answers. Node.js is here to stay and this article will help you prepare for your interview better.