🚀 React Interview Experience (July 2025): Sparx IT

Overview

This document outlines a React developer interview experience at Sparx IT in July 2025. The interview process assessed the candidate's knowledge of various frontend technologies and concepts. The questions spanned fundamental CSS principles to advanced React features and tooling.

Interview Rounds

The interview included questions across a broad spectrum of frontend development topics. Here's a breakdown:

• CSS Fundamentals: Questions focused on line-height, pseudo-classes/elements, positioning (relative, absolute, fixed, sticky), SASS/SCSS, and responsive design techniques.

• React Core Concepts: The candidate was questioned on useEffect cleanup functions, the difference between useReducer and useState, Redux workflow, static site generation (SSG), server-side rendering (SSR), and updates in React 19.

• Next.js: The interviewer explored the reasons for using Next.js, highlighting its SSR/SSG capabilities and built-in features.

• React Component Communication: Questions addressed passing data from child to parent components using callback functions and the purpose of forwardRef.

• Code Optimization: Code splitting was discussed as a performance optimization technique.

• TypeScript: The interviewer assessed the candidate's understanding of interfaces and type annotations.

• JavaScript Fundamentals: The questions covered prototypes, Axios interceptors, event bubbling, hoisting, and object manipulation.

Here's a detailed list of questions:

CSS

1. What is line-height in CSS?
2. What are pseudo-classes and pseudo-elements in CSS? Give Examples.
3. What is the difference between relative, absolute, fixed, and sticky positioning in CSS?
4. What is SASS/SCSS?
5. What is rem in CSS?
6. How would you make a website responsive?

React

7. What is the use of return inside useEffect?
8. Difference between useReducer and useState.