Node.js Questions

Here are some of the most common and high-impact questions you might encounter in your interviews. These key questions frequently start conversations and are favorites among interviewers. Prepare well, and you'll be ready to impress!

Table of Contents

1. What is Node.js?

What is Node.js?

Node.js is a JavaScript runtime built on Chrome's V8 engine, allowing developers to run JavaScript code outside of a browser. It's designed for building scalable and efficient network applications.

Node.js Architecture Overview

1. Request Flow:

   • Clients send requests to the Node.js server.
   • Requests are stored in the Event Queue using a First-Come, First-Served (FCFS) method.

2. Event Loop:

   • Processes requests from the Event Queue.
   • Differentiates between blocking and non-blocking requests.

Request Types

Non-Blocking Requests:

• Executed asynchronously; the program continues without waiting.
• The Event Loop handles these requests quickly, allowing other operations to proceed.

Blocking Requests:

• Executed synchronously; the program pauses until completion.
• A thread processes the request, and responses are sent back to clients.
• Default thread pool size is 4 (can increase based on CPU cores).

Challenges with Blocking Requests:

• Increased client load can exhaust limited threads, causing delays.
• Prefer non-blocking requests to avoid user wait times and improve experience.

Recommendation:

• Aim to make most requests non-blocking to enhance application scalability and user experience.