TCS Node JS Developer Interview Questions, Process, and Tips

Q1. How node.js works
Ans. 
Node.js is a runtime environment that allows JavaScript code to run on the server-side.
• Node.js uses an event-driven, non-blocking I/O model, making it lightweight and efficient.

• It uses the V8 JavaScript engine from Google Chrome to execute code.

• Node.js allows developers to build scalable network applications using JavaScript.

• It has a large ecosystem of libraries and frameworks, such as Express.js for web applications.
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Q2. What is event loop in Node.js
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Event loop in Node.js is a mechanism that allows Node.js to perform non-blocking I/O operations.
• Event loop is responsible for handling asynchronous operations in Node.js.

• It allows Node.js to perform multiple operations concurrently without blocking the execution.

• Event loop continuously checks the event queue for any pending events and executes them in a loop.

• Example: When reading a file in Node.js, the event loop allow...read more
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Q1. How to deploy node.js application
Ans. 
Node.js applications can be deployed using various methods such as using a hosting service, containerization, or serverless platforms.
• Use a hosting service like Heroku, AWS, or DigitalOcean to deploy the application.

• Containerize the application using Docker and deploy it on a container orchestration platform like Kubernetes.

• Utilize serverless platforms like AWS Lambda or Google Cloud Functions for deploying serverless
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Q2. List AWS services used
Ans. 
Some AWS services commonly used by Node JS developers are EC2, S3, Lambda, RDS, and API Gateway.
• EC2 (Elastic Compute Cloud) for scalable virtual servers

• S3 (Simple Storage Service) for object storage

• Lambda for serverless computing

• RDS (Relational Database Service) for managed databases

• API Gateway for creating, publishing, maintaining, monitoring, and securing APIs
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Q1. What is a callback function?
Ans. 
A callback function is a function passed as an argument to another function, which will be executed at a later time.
• Used in asynchronous programming to handle tasks that take time to complete

• Allows functions to be executed after another function has finished

• Commonly used in Node.js for handling I/O operations
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Q2. Output of setTimeout Js Function?
Ans. 
setTimeout function in JavaScript executes a function after a specified delay.
• setTimeout function takes two parameters: a function to be executed and a delay in milliseconds.

• The function is executed only once after the specified delay.

• Example: setTimeout(() => { console.log('Hello, World!'); }, 2000); // Output: 'Hello, World!' after 2 seconds
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Node.js. mongodb

Q1. Multi processing in node
Ans. 
Node.js uses child processes for multi-processing to take advantage of multiple CPU cores.
• Node.js uses child processes to run multiple instances of the application in parallel.

• The 'cluster' module can be used to create a pool of worker processes to handle incoming requests.

• Using child processes allows Node.js to take advantage of multiple CPU cores for better performance.
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