🚀 React Interview Experience (August 2025): CapGemini (Part -5)

Overview

This article presents a React developer interview experience at CapGemini in August 2025. The interview focused on core frontend technologies, including React, Redux, and TypeScript, along with fundamental JavaScript concepts and problem-solving skills.

Interview Rounds

The interview included questions spanning various aspects of frontend development. Here's a breakdown of the topics covered:

• TypeScript:
  • The candidate was asked why TypeScript doesn't run directly in the browser and the necessity of a compilation step to JavaScript.
• Redux:
  • The function of dispatch in Redux was discussed, including its role in sending actions to the store.
  • The candidate was questioned on methods for utilizing APIs created in Redux within React components, covering both createSlice with Thunks and RTK Query API approaches.
• React Fundamentals:
  • The task of creating a basic React counter application was assigned, requiring the use of useState for state management.
  • The role and usage of Ref and forwardRef in React were explored, emphasizing direct DOM access and component interaction.
• JavaScript Concepts:
  • The candidate was asked to write a function to find a missing number in an array, with solutions using both Sum Formula and XOR approaches.
  • The candidate was asked to write a function to find the frequency of repeated numbers in an array.
  • The Redux application architecture was explained, emphasizing the unidirectional data flow and the roles of actions, reducers, and the store.
  • Hoisting in JavaScript was defined, detailing its behavior with var, let, const, function declarations, and function expressions.
• General Frontend Development:
  • The candidate was asked about different techniques to create a responsive webpage design using CSS media queries, Flexbox/Grid layouts, relative units and mobile-first design.

Key Takeaways

• A strong understanding of TypeScript compilation and its role in frontend development is crucial.
• Proficiency in Redux, including state management and API integration using both traditional Thunks and RTK Query, is expected.
• Solid React fundamentals, such as state management with useState and DOM manipulation with Refs, are essential.
• A firm grasp of core JavaScript concepts like hoisting and array manipulation techniques is necessary.
• Knowledge of responsive design principles is vital for creating adaptable user interfaces.