🚀 React Interview Experience (August 2025): Saksoft Ltd. (Part-5)

Overview

This document details a React developer interview experience at Saksoft Ltd. in August 2025. The interview focused on core React concepts, optimization techniques, testing methodologies, and problem-solving skills. This breakdown aims to provide a valuable resource for frontend developers preparing for similar roles.

Interview Rounds

The interview process included questions designed to assess the candidate's understanding of React and related technologies. Key areas explored during the interview are detailed below:

React and Redux

Q 33. What are the disadvantages of Redux?

The candidate was asked to outline the drawbacks of using Redux for state management. The expected answer included points such as boilerplate code, complexity for smaller applications, a steep learning curve, extra setup requirements, potential performance overhead, and debugging challenges with asynchronous logic.

Application Configuration

Q 34. How are you managing the configuration part of your React application?

The candidate described managing configuration using environment variables and separate config files. The approach included storing sensitive data in .env files, accessing them via process.env.REACT_APP_*, and using a config.js file to centralize application configuration. Security best practices, such as excluding .env files from version control and using secret managers, were also discussed.

Performance Optimization

Q 35. What are the steps you need to take to optimize the performance of a React application?

The response covered several optimization techniques, including avoiding unnecessary re-renders using React.memo, useCallback, and useMemo. The candidate also mentioned code splitting with React.lazy and Suspense, virtualization for large lists, efficient state management, image optimization, bundle size reduction, memoization, debouncing/throttling, server-side rendering (SSR)/static site generation (SSG), production builds, and performance profiling with React DevTools.

Testing Strategies

Q 36. How are you doing the testing for your application and for your site, what are the tools you are using for testing?

The candidate outlined a layered testing approach encompassing unit, integration, and end-to-end (E2E) testing. Tools mentioned included Jest and React Testing Library (RTL) for unit testing, RTL with mocked API calls (using msw) and Jest for integration testing, and Cypress and Playwright for E2E testing. Performance and accessibility testing with Lighthouse and axe-core, and API testing with Postman and Newman, were also discussed. The importance of CI/CD integration for automated testing was emphasized.

Responsiveness Testing

Q 37. Suppose the pages that you are building are loading properly on all the devices. How will you check the responsiveness of the application?

The candidate explained methods for ensuring responsiveness, including using browser DevTools to simulate different devices and CSS breakpoints. The use of Flexbox and CSS Grid for layouts, media queries, React libraries like react-responsive, real device testing, cross-browser testing, performance testing on low-end devices, and automated visual testing tools were all mentioned.

Problem Solving

Q 38. Suppose I am giving you 10 chocolates initially, And I am giving you an offer that if you are returning three chocolate wrappers back to me I will give you one more chocolate in exchange of those three wrappers. Calculate out of those 10 chocolates how many extra chocolates you can get through that exchange process.

The candidate provided a JavaScript function to calculate the maximum number of chocolates obtainable through the exchange process. The function iteratively determines the number of extra chocolates gained by exchanging wrappers and updates the remaining wrappers accordingly. An example with 10 initial chocolates and a wrapper exchange rate of 3 resulted in a total of 14 chocolates.

Key Takeaways

• A strong understanding of React fundamentals, including state management with Redux, is crucial.
• Experience with performance optimization techniques is highly valued.
• Knowledge of various testing methodologies and tools is essential for ensuring application quality.
• Problem-solving skills and the ability to articulate technical solutions are important.
• Understanding of CI/CD and automated testing pipelines is beneficial.