Node.js is an open-source, cross-platform, single-threaded, backend JavaScript runtime environment and library. Node.js executes the JavaScript code outside the client’s web browser and runs on the V8 engine. Since Node.js is single-threaded, it’s mainly used for non-blocking, event-driven servers.
We can use Node.js to create server-side data-intensive applications due to its asynchronous and event-driven model. We can also use it for developing distributed systems, general-purpose, real-time, and network applications. This article focuses on senior Node JS developer interview questions to help you prepare.
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In this article, we’ll cover:
We’ll begin with some basic Senior Node JS Developer interview questions and answers to get an idea of what to expect.
Node.js indeed spawns child threads for some tasks like asynchronous I/O. However, they run behind the scenes without executing any JavaScript code in the application and without blocking the main event loop.
Node.js is a single-threaded process. It does not expose thread management methods and child threads to the developer. Tools enable threading support in a Node.js application like the ChildProcess module. Node.js 12 also offers experimental support for threads.
The control flow function is a function, a block of code, that runs in between several asynchronous function calls. The control flow controls the order of execution, collects information, limits concurrency, and calls the next step in a program.
We use Node.js most frequently in IoT, Complex SPAs, real-time chats, real-time collaboration tools, microservices architecture, and streaming applications.
Asynchronous, non-blocking, and synchronous blocking functions are the two types of API functions in Node.js.
setTimeout or clearTimeout, setInterval or clearInterval, and setImmediate or clearImmediate are three functions provided by the Timers module for executing code after a specific period.
Now, here are some sample Senior Node JS Developer interview questions. See if you can solve them:
Let’s move a step further with some Senior Node JS Developer interview questions for experienced professionals:
Lastly, here are some technical Senior Node JS Developer interview questions. Ensure you can solve them before your interview:
Q1. What should a senior Node.js developer know?
A senior Node.js developer should have experience in front-end design and development using HTML and CSS. A senior Node.js developer is also expected to know crucial JavaScript concepts and have error-handling skills. They should also have the necessary skills associated with RESTful APIs and API communications.
Q2. Name a database that’s popularly used with Node.js.
MongoDB is a cross-platform, NoSQL, document-oriented database most commonly used with Node.js. Its advantages include high availability, high performance, and ease of scalability.
Q3. Why is Node.js Single-threaded? Is Node.js synchronous or asynchronous?
Node.js is asynchronous and is single-threaded to enable async processing. Async processing on a single thread under usual web loads allows us to achieve more performance and scalability than the general thread-based implementation.
Q4. What is REPL in Node.js?
REPL refers to Read, Eval, Print, and Loop in Node.js.
Q5. Why should we use Node.js?
Node.js is fast, asynchronous, rarely blocks, yields great concurrency, offers a unified language and data type, and eases the process of building scalable network programs.
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