🚀 Frontend Developer (4 Years Experience) – Interview Questions I Was Asked Recently, I interviewed for a Frontend Developer role (4+ years experience), and I wanted to share some important questions that were asked—along with short insights that might help others preparing for similar roles. 🔹 1. Difference between var, let, and const 👉 Scope, hoisting behavior, and immutability were key discussion points. 🔹 2. How does React reconciliation work? 👉 Understanding the Virtual DOM, diffing algorithm, and why keys matter. 🔹 3. What are React Hooks? Which ones do you use most and why? 👉 useState, useEffect, useMemo, useCallback, and custom hooks with real use cases. 🔹 4. How do you optimize performance in a React application? 👉 Code splitting, memoization, lazy loading, avoiding unnecessary re-renders. 🔹 5. Explain controlled vs uncontrolled components 👉 When to use which and how forms are handled efficiently. 🔹 6. What is debouncing and throttling? 👉 Real-world examples like search inputs and scroll events. 🔹 7. How does browser rendering work? 👉 Critical Rendering Path: HTML → CSS → DOM → Render Tree → Paint. 🔹 8. How do you handle state management in large applications? 👉 Context API vs Redux / Toolkit, and when not to overuse global state. 🔹 9. Difference between REST and GraphQL (if applicable) 👉 Over-fetching, under-fetching, and flexibility. 🔹 10. How do you ensure code quality? 👉 Reusable components, ESLint, Prettier, clean folder structure, and reviews. ✨ Key takeaway: Interviewers don’t just test syntax—they focus on problem-solving, optimization, and real-world experience. If you’re a frontend developer with 3–5 years of experience, make sure you understand why things work, not just how. Hope this helps someone preparing for interviews! Feel free to add more questions in the comments 👇 #FrontendDeveloper #ReactJS #JavaScript #WebDevelopment #InterviewExperience #CareerGrowth
🔹 1. Difference between var, let, and const 🔹 3. What are React Hooks? Which ones do you use most and why? I have 3+ YOE. Why does my interviewer start in the most harsh ways with me? And everyone gets smooth ones. My first question: Explain fetch vs axios vs curl. My second question: How does React work behind the scenes? My third, at which I prefer to cut my nerves: What is damn Recursion & write a code. Are they targeting me?
We ask these questions to freshers 🤨
I am sorry to say but this is not usual questions that asked in FE now a days, they directly ask how did you optimize re render , can you write a function to deepclone an object,etc but it depends on your luck
But this looks too basic for 4 yr experienced candidate were these the only questions that were asked or first few questions
hi akanksha, thank you for posting this. i'm preparing for interviews and this will be helpful.
These questions looks common onces. Is these the question asked for 4 years of exp guy ?
Thanks for sharing this..
Interested
Great insights ✌️
Wow, these are not that difficult. Was that a big firm?