🚀 React Interview Experience (August 2025): HCL(Part -4)

Overview

This document provides a detailed account of a React Developer interview conducted at HCL in August 2025. The interview focused on assessing the candidate's understanding of React fundamentals, their ability to implement best practices, and their experience with building scalable and maintainable frontend applications. The questions ranged from basic React concepts to advanced topics like lazy loading, server-side rendering, and internationalization.

Interview Rounds

The interview process included questions covering the following key areas:

• React Initialization: The candidate was asked to describe how a React application is built upon initial setup, including the tools used and the sequence of events from project initialization to UI rendering.
• Lazy Loading: The candidate was questioned on how to implement lazy loading in React to optimize initial load times, including the use of React.lazy() and Suspense.
• Backend Integration: The interview explored how to integrate a React frontend with backend servers like Node.js or Django, focusing on API design, environment configuration, and authentication.
• Rendering Techniques: The candidate was asked to explain the differences between Client-Side Rendering (CSR), Server-Side Rendering (SSR), and Static Site Generation (SSG), including their respective advantages and disadvantages.
• Internationalization (i18n): The interview covered the concept of i18n and how to implement it in a React application using libraries like react-i18next.

Specific Questions and Answers:

Q16: When you first initialize, how will the application be built using React?

The candidate explained the step-by-step breakdown, including:

1. Project Initialization: Using tools like npx create-react-app or npm create vite@latest. Mentioning the preference for Vite with TypeScript.
2. Build/Compile Phase: Detailing JSX/TSX compilation by Babel or ESBuild, bundling, and the use of a dev server with Hot Module Replacement (HMR).
3. ReactDOM Renders App: Showing how React mounts the root component using ReactDOM.createRoot.
4. Component Mounting and Lifecycle Begins: Describing the lifecycle methods for class and functional components.
5. UI Appears in Browser: Explaining how React updates the DOM using its Virtual DOM.

The answer also included an outline of an enterprise-ready setup with modular folder structure, TypeScript, state management, API layer, routing, linting/formatting, testing, CI/CD pipeline, and environment configurations.

Q17: How will you implement Lazy loading in React?

The candidate detailed the use of React.lazy() with Suspense for component-level lazy loading, lazy-loading pages using React Router, and splitting code using dynamic imports with webpack or Vite chunking.

Q18: How do you integrate React with a backend server like Node.js or Django?

The candidate explained the RESTful or GraphQL-based architecture, API layer, environment configuration, fetch layer using Axios or fetch(), CORS handling, and token-based authentication.

Q19: Can you explain the difference between Client-Side Rendering, Server-Side Rendering and Static Site Generation?

The candidate clearly defined the differences between CSR, SSR, and SSG, highlighting the pros and cons of each approach.

Q20: What is Internationalization (i18n)?

The candidate defined i18n and explained how to implement it using libraries like react-i18next, including the use of language JSON files and translation components.

Key Takeaways

• A strong understanding of React fundamentals is crucial.
• Experience with optimization techniques like lazy loading is highly valued.
• Knowledge of backend integration strategies is essential for full-stack development.
• The ability to differentiate between rendering techniques demonstrates a comprehensive understanding of web application architecture.
• Familiarity with internationalization principles is increasingly important for global applications.