TCS
Large multinational IT services and consulting enterprise based in India.
3 Rounds
~14 Days
Medium
The Interview Loop
Recruiter Screen (30 min)
Standard fit check, behavioral questions, and resume overview.
Technical Loop (3-4 Rounds)
Deep dive into domain knowledge, coding, and system design.
Interview Question Bank
Frontend Engineer
•
Behavioral
•
medium
Tell me about a time you had to push back on a client or product manager regarding an unrealistic deadline. How did you handle it?
#Communication
#Agile
#Stakeholder Management
Frontend Engineer
•
Behavioral
•
medium
Describe a situation where you had a conflict with a backend developer regarding an API contract or data format. How was it resolved?
#Teamwork
#Conflict Resolution
#API Design
Frontend Engineer
•
Behavioral
•
easy
How do you stay updated with the latest frontend technologies, and how do you decide when it is safe to adopt a new tool in a large enterprise project?
#Continuous Learning
#Risk Assessment
#Tech Stack
Frontend Engineer
•
Behavioral
•
medium
Tell me about a time you were assigned to a project with poorly documented, legacy code written by a previous vendor. How did you approach understanding and optimizing it?
#Legacy Code
#Refactoring
#Adaptability
Frontend Engineer
•
Behavioral
•
easy
Explain a time when you had to mentor a junior developer who was struggling to grasp complex React concepts like Hooks or Redux.
#Mentorship
#Empathy
#Knowledge Sharing
Frontend Engineer
•
Coding
•
hard
Implement a custom Promise.all() polyfill.
#Promises
#Asynchronous JavaScript
#Polyfills
Frontend Engineer
•
Coding
•
medium
Write a JavaScript function to flatten a deeply nested array without using the built-in Array.prototype.flat() method.
#Recursion
#Arrays
#Data Structures
Frontend Engineer
•
Coding
•
medium
Implement a debounce function from scratch. How does it differ from throttling, and when would you use each?
#Performance
#Higher-Order Functions
#DOM Events
Frontend Engineer
•
Coding
•
hard
Write a function to deep clone a nested JavaScript object. How would you modify it to handle circular references?
#Objects
#Recursion
#Memory Management
Frontend Engineer
•
Coding
•
hard
Implement an LRU (Least Recently Used) Cache class in JavaScript with get() and put() methods operating in O(1) time complexity.
#Data Structures
#Caching
#Hash Maps
#Linked Lists
Frontend Engineer
•
Coding
•
medium
Design and implement a custom React hook called 'useFetch' that takes a URL and returns data, loading, and error states. Include basic caching.
#Custom Hooks
#API Integration
#State Management
Frontend Engineer
•
Coding
•
medium
Write a React component that fetches a list of users from an API and renders them. Implement pagination (Next/Previous buttons) and handle loading/error states.
#Component Design
#Pagination
#API Integration
Frontend Engineer
•
System Design
•
hard
Design the frontend architecture for a real-time stock trading dashboard. Focus on data fetching, state management, and performance.
#WebSockets
#Real-time Data
#Architecture
Frontend Engineer
•
System Design
•
hard
A major retail client at TCS wants to migrate their monolithic frontend to a Micro-frontend architecture. How would you architect this?
#Micro-frontends
#Webpack Module Federation
#Scalability
Frontend Engineer
•
System Design
•
medium
Design an autocomplete search bar component for an e-commerce site. Consider network latency, caching, and race conditions.
#Component Design
#Debouncing
#Caching
Frontend Engineer
•
System Design
•
hard
Design a scalable file upload component that supports drag-and-drop, progress bars, chunking for large files, and resumable uploads.
#File Handling
#Network Requests
#UX
Frontend Engineer
•
System Design
•
medium
How would you implement offline support for a web application used by field workers with intermittent internet connectivity?
#Service Workers
#PWA
#IndexedDB
Frontend Engineer
•
Technical
•
medium
Explain prototypal inheritance in JavaScript. How do ES6 classes differ from traditional constructor functions under the hood?
#Prototypes
#OOP
#ES6
Frontend Engineer
•
Technical
•
medium
Explain the event loop in JavaScript. What will be the output of a script containing synchronous logs, a setTimeout, and a Promise.resolve().then()?
#Event Loop
#Microtasks
#Macrotasks
Frontend Engineer
•
Technical
•
easy
What are closures in JavaScript? Provide a real-world use case where you would use a closure in an enterprise application.
#Closures
#Scope
#Lexical Environment
Frontend Engineer
•
Technical
•
easy
What is the difference between '==' and '===' in JavaScript? How does type coercion work under the hood?
#Type Coercion
#Equality
#Fundamentals
Frontend Engineer
•
Technical
•
medium
How does the 'this' keyword work in JavaScript? Explain how its behavior changes between regular functions, arrow functions, and event listeners.
#Context
#Arrow Functions
#Execution Context
Frontend Engineer
•
Technical
•
medium
Explain the difference between useMemo and useCallback in React. Provide a scenario where misusing them could actually degrade performance.
#Hooks
#Performance Optimization
#Memoization
Frontend Engineer
•
Technical
•
medium
How does React's Virtual DOM work? Why is it considered faster than direct DOM manipulation?
#Virtual DOM
#Reconciliation
#Rendering
Frontend Engineer
•
Technical
•
easy
What is Prop Drilling in React? What are the various strategies to avoid it in a large-scale enterprise application?
#Component Architecture
#State Management
#Context API
Frontend Engineer
•
Technical
•
medium
Explain the core principles of Redux. Walk me through the exact flow of data from a React component dispatching an action to the UI updating.
#Redux
#Flux Architecture
#Immutability
Frontend Engineer
•
Technical
•
medium
How do you handle asynchronous side effects in Redux? Compare Redux Thunk with Redux Saga.
#Redux Middleware
#Asynchronous Logic
#Generators
Frontend Engineer
•
Technical
•
hard
What are React Server Components (RSC)? How do they differ from traditional Server-Side Rendering (SSR) in frameworks like Next.js?
#Server Components
#Next.js
#Rendering Strategies
Frontend Engineer
•
Technical
•
easy
Map the traditional React class component lifecycle methods (componentDidMount, componentDidUpdate, componentWillUnmount) to their functional component Hook equivalents.
#Lifecycle
#Hooks
#useEffect
Frontend Engineer
•
Technical
•
hard
You are assigned to a legacy React application at TCS that is rendering very slowly. What specific steps and tools would you use to profile and optimize it?
#Profiling
#Optimization
#React DevTools
Frontend Engineer
•
Technical
•
easy
Explain CSS Specificity. If a div has an ID, a class, and an inline style, which rule applies and why? How does '!important' affect this?
#Specificity
#Cascading
#Styling
Frontend Engineer
•
Technical
•
medium
Compare CSS Grid and Flexbox. In a responsive dashboard layout, when would you choose Grid over Flexbox?
#Layouts
#Flexbox
#CSS Grid
Frontend Engineer
•
Technical
•
medium
How do you ensure a web application is accessible (a11y) for users relying on screen readers? Name at least 5 best practices.
#a11y
#ARIA
#Semantic HTML
Frontend Engineer
•
Technical
•
medium
Explain Cross-Site Scripting (XSS). How would you prevent XSS attacks in a modern Single Page Application?
#Security
#XSS
#Sanitization
Frontend Engineer
•
Technical
•
hard
What are Core Web Vitals? Specifically, explain Largest Contentful Paint (LCP) and strategies to improve a poor LCP score.
#Core Web Vitals
#LCP
#SEO
Difficulty Radar
Based on recent AI-sourced data.
Meet Your Interviewers
The "Standard" Interviewer
Senior EngineerFocuses on core competencies, system constraints, and clear communication.
SimulateUnwritten Rules
Think Out Loud
Always explain your thought process before writing code or drawing architecture.