🚀 React Interview Experience (August 2025): L & T(Part -1)
Richa Gautam 🌷
January 8, 2026
medium
Overview
This document outlines the interview experience for a React Developer position at L & T (Larsen & Toubro) in August 2025. The interview focused on core React concepts, JavaScript fundamentals, state management, performance optimization, error handling, and design patterns. The candidate's responses provide a valuable resource for developers preparing for similar roles.
Interview Rounds
The interview process included questions covering a range of frontend development topics:
React Fundamentals:
- Question 1: What is React, and how does it compare to other tools?
- The candidate correctly defined React as an open-source JavaScript library for building user interfaces, emphasizing its component-based architecture, virtual DOM, unidirectional data flow, strong ecosystem, and JSX syntax.
- Question 2: Can you elaborate on component-based architecture?
- The candidate explained the principles of component-based architecture, including encapsulation, reusability, composability, and maintainability.
- Question 3: What are React Hooks?
- The candidate accurately described React Hooks as functions that enable the use of state and other React features in functional components, highlighting
useState,useEffect,useContext,useRef,useMemo, anduseCallback.
- The candidate accurately described React Hooks as functions that enable the use of state and other React features in functional components, highlighting
- Question 4: How do you handle state management?
- The candidate detailed different state management approaches based on application complexity, including local state (
useState,useReducer), global state (Context API, Redux, Zustand), server state (React Query), and URL state (React Router).
- The candidate detailed different state management approaches based on application complexity, including local state (
- Question 5: In order to optimize performance, how can you achieve it in React?
- The candidate outlined various optimization techniques, including memoization (
React.memo,useMemo,useCallback), lazy loading & code splitting (React.lazy,Suspense), efficient lists (key props, windowing), avoiding reconciliation, batched updates (React 18+), and the use of React DevTools Profiler.
- The candidate outlined various optimization techniques, including memoization (
JavaScript Fundamentals:
- Question 6: Write a function to reverse a string.
- The candidate provided two solutions: one using built-in methods and another without, demonstrating a strong understanding of string manipulation.
- Question 7: How do you handle errors?
- The candidate described error handling strategies for synchronous code (try-catch), asynchronous code (.catch() in Promises, try-catch in async-await), React components (Error Boundaries), logging (Sentry, LogRocket), validation, and fallback UI.
- Question 8: Can you add error handling in the reverse string function?
- The candidate enhanced the
reverseStringfunction with error handling, including type checking and a try-catch block.
- The candidate enhanced the
Design Patterns:
- Question 9: Have you worked on design patterns?
- The candidate cited experience with the Singleton, Factory, Observer, Strategy, HOC & Render Props, and Module patterns.
- Question 10: What is the Factory pattern?
- The candidate explained the Factory Pattern as a creational design pattern for creating objects without specifying the exact class. They provided a JavaScript example and a React-specific use case with button components.
Key Takeaways
- A strong understanding of React fundamentals is crucial, including components, hooks, and state management.
- Knowledge of performance optimization techniques is essential for building efficient React applications.
- Experience with error handling strategies is vital for creating robust and user-friendly applications.
- Familiarity with common design patterns improves code quality, reusability, and maintainability.
- Being able to articulate solutions with and without built-in methods showcases a deeper understanding of the underlying logic.
Original Source
This experience was originally published on medium. Support the author by visiting the original post.
Read on medium