Interview Experience - Flipkart | Front End Engineer | SDE 2

Summary:

• 📌 Job Role: Front End Engineer (UI2 / WDE2)

• 🔢 Number of Rounds: 5

• 📜 Offer Status: Rejected

• 📍 Location: —

• 👤 Candidate Name: Not disclosing due to signed NDA

Interview Process

The interview process at Flipkart for the UI2 / WDE2 / Front End Engineer 2 position spanned 5 rounds, covering a broad range of topics including machine coding, data structures, UI-specific technical depth, product thinking, and behavioral aspects. Here's a breakdown:

1. Machine Coding and Review (2 hours)

2. Problem Solving - Data Structures (PS-DS)

3. UI Tech

4. Product Sense

5. Hiring Manager

Each round tested different aspects — from hands-on frontend coding, core JavaScript concepts, system design at a UI level, product sensibility, and finally alignment with team fit and experience.

Preparation Guide

• Used Webpack with hot reload to quickly iterate and live preview during machine coding rounds.

• Organized the project with modular code structure and a clean folder hierarchy.

• Focused more on trees, DFS, BFS, and recursion, as DOM manipulation problems can often translate into tree problems.

• For JavaScript depth, concentrated on closures, this, and prototypes.

• Followed this Udacity course on JavaScript: https://classroom.udacity.com/courses/ud860

• Referenced Safari books on webpage optimization for web vitals and frontend performance.

• Practiced product scenarios to improve creativity and communication in Product Sense rounds.

• Stayed mindful of staying on track during open-ended conversations, especially in product-based rounds.

Interview Rounds

Round 1: Machine Coding and Review

• Duration: 120 Minutes

• Difficulty Level: Easy

Experience:

This was a hands-on coding round. The task was to build a small frontend application using plain HTML, CSS, and JavaScript. The question was uploaded in advance and can be found here. The emphasis was on implementing a fully functional app with readable and maintainable code. The interviewer was actively reviewing the code and gave instant feedback on naming conventions, folder structure, and modularity.

The code was reviewed live, and feedback was given in real time. The interviewer appreciated the way the code was organized and the approach towards problem-solving. Overall, this round went quite smoothly.

Key Learnings:

• Use Webpack + Hot Reload for faster development.

• Focus on a clean modular folder structure.

• Real-time feedback in code reviews makes a significant difference in impression.

Round 2: PS-DS

• Duration: 60 Minutes

• Difficulty Level: Medium

Experience:

This round was a mix of asynchronous JavaScript challenges, tree traversal, and understanding the underlying behavior of React.

1. Given an array of functions returning promises, implement a method to run them:

   • In parallel.

   • Sequentially, without using async/await. Solved this using recursion.

2. A variation of Employee Importance (Link) involving referral bonus calculation in an n-ary tree structure.

3. Discussed React’s reconciliation and how virtual DOM might work under the hood.

   • Follow-up problem was a variant of this, but with an n-ary tree.

4. Wrote a curried function like sum(2)(3)(4)() which returns 9.

Key Learnings:

• DOM structures often map to n-ary trees. Practicing DFS/BFS helps.

• Be comfortable with recursion and functional programming in JavaScript.

• React internals are fair game — know how reconciliation and the virtual DOM operate.

Round 3: UI Tech

• Duration: 60 Minutes

• Difficulty Level: Medium

Experience:

This was a deep dive into frontend-specific concepts.

1. Implemented Promise.all from scratch and discussed edge cases.

2. Questions around memoization, debouncing, throttling, and the use of this.

3. CSS-based question to center elements both vertically and horizontally using flex.

4. Briefly discussed web performance optimization and concepts like web vitals, critical rendering path, and lazy loading.

Key Learnings:

• Brush up core JavaScript, especially concepts like closures, context (this), and promises.

• Know how to build layout patterns using CSS Flexbox.

• Web performance is an important topic — having clear strategies helps in UI rounds.

Round 4: Product Sense

• Duration: 45 Minutes

• Difficulty Level: Difficult

Experience:

This round felt more like a PM interview than an engineering one. The scenario was:

"Design a 2-player game where each player can have multiple fighters. What features would you add? How would you prioritize them (P0, P1, P2)?"

This required product thinking, prioritization, and a balance between creativity and feasibility. Since I don’t play many games, I struggled to generate interesting ideas or communicate them effectively. The conversation was dynamic and exploratory, moving towards topics like:

• Booking systems

• Photo sharing platforms

• Trade-offs in MVPs

Key Learnings:

• Product Sense interviews are not just for PMs.

• Practice brainstorming product features, user flows, and MVP prioritization.

• Communication is key — it’s not just what you say, but how you express your rationale.

Round 5: Hiring Manager

• Duration: 60 Minutes

• Difficulty Level: Medium

Experience:

A balanced round between behavioral and technical.

• Discussed my current and past work, team contributions, and challenges faced.

• Talked about mentorship, and how I’ve handled conflicts at work.

• Then moved into technical topics like:

  • Web security

  • Frontend performance tuning

  • How I would integrate a third-party payment system like Stripe into Flipkart’s architecture.

The interviewer seemed interested in my past experiences but also wanted to gauge decision-making, especially around ownership and system-level thinking.

Key Learnings:

• Behavioral rounds can be detailed — have stories ready that show impact and ownership.

• Security and performance are essential when you talk about real-world implementation.

• Know at least one payment gateway integration flow in detail.

Final Thoughts

This Flipkart interview was a comprehensive experience, covering everything from hands-on coding to product and communication skills. Here are a few closing thoughts:

• Don’t underestimate product sense rounds in frontend roles.

• DOM = Tree → Prepare tree problems and recursion well.

• Have a mental model for layout systems (Flex/Grid), JS fundamentals, and real-world app performance.

• Preparation for interviews like these must balance depth and breadth — know your fundamentals well but also be prepared for open-ended and high-level discussions.

• It’s okay if some rounds don’t go well — each round is a learning experience.