Frontend Engineer Interview — Round 2 Experience (React + System Thinking) I had my Round 2 for a Frontend Engineer (React) role, and this one shifted toward deeper thinking — architecture, debugging, and React internals. Here’s what the interview looked like 👇 🧠 Core Discussion Topics 🔹 1. React Rendering Behavior — Why does a component re-render? — How React decides when to skip rendering — React.memo, useMemo, useCallback — when (and when NOT) to use them 🔹 2. How the Browser Works — Critical Rendering Path — Layout → Paint → Composite — What triggers reflow? — Why transform + opacity are preferred for animations 🔹 3. State Management Choices They asked: “Why did you choose Context or Redux Toolkit in your project?” I explained trade-offs: ✔ Context: Simple global state ✔ Redux Toolkit: Predictable updates, debugging, middleware 💻 Coding Tasks 1️⃣ Implement debounce() from scratch function debounce(fn, delay) { let timer; return (...args) => { clearTimeout(timer); timer = setTimeout(() => fn(...args), delay); }; } 2️⃣ Convert a nested category list into a flattened structure Tests recursion + data transformation + clean thinking. 🎯 Takeaways This round checked for: ✔ Problem-solving ✔ How deeply I understand React internals ✔ My ability to reason about performance ✔ Thinking like a product-focused engineer I enjoyed this round because it wasn’t just about writing code, it was about explaining how I think. 👉 Follow Rahul R Jain for more frontend interview breakdowns, live examples, and React/Next.js insights. hashtag#FrontendInterview hashtag#ReactJS hashtag#JavaScript hashtag#NextJS hashtag#InterviewExperience hashtag#W