Full Stack Developer Interview Experience

I interviewed at Google, Uber, Walmart, Amazon and several top startups (a total of 60+ interviews) during my job search from March to June 2025 before joining Atlassian as a Principal Engineer. Here’s what each experience taught me. If you’re prepping for a switch, I hope this gives you clarity on what to expect (and how to survive the roller coaster): [1] Google (L5) ○ Offer Verdict: Not offered ○ Both rounds were deep dives into trees/BSTs and circular buffer implementations. ○ I ended up over-complicating my code, focusing on perfect edge-case handling instead of moving forward. ○ Lost track of time, which cost me the chance to showcase my strengths. ○ Sometimes, you need to show breadth before depth. [2] Uber (L5a) ○ Offer Verdict: Not offered ○ Honestly, the environment was tough: the interviewer was rigid and not open to dialogue. ○ Started with a brutal BST cost optimization DP, hit a wall early and couldn’t recover. ○ Only got momentum on the second question, but the clock had already run out. ○ Not every room is fair, but you’ve got to play the hand you’re dealt. [3] Amazon (L6) ○ Offer Verdict: Offered ○ From the start, leadership principles were baked into every question. ○ Coding was challenging, but behavioral rounds tested my ability to own up to mistakes and learn from failure. ○ The bar-raiser loop pushed for specifics, what did I do, how did I decide, what did I learn? ○ At this level, they want to see if you’ll drive change, not just write code. [4] Walmart (Staff) ○ Offer Verdict: Offered ○ Coding round seemed basic at first, until edge cases and perf requirements kicked in. ○ Subsequent rounds focused on both granular (LLD) and high-level (HLD) architecture. ○ Hiring Manager discussions went deep into how I handle ambiguous requirements. ○ The difference? Anticipating what can go wrong and showing how you think in the grey areas. [5] Atlassian (Principal) ○ Offer Verdict: Offered ○ The bar here was full spectrum: system design, core DSA, LLD, behavioral, and true leadership interviews. ○ I was tested on scale, “what if usage spikes 100x?”, and had to justify every major design call. ○ What stood out: They valued holistic, end-to-end thinking, not just technical correctness. [6] Salesforce (LMTS) ○ Offer Verdict: Offered ○ Hackerrank and coding rounds were rigorous but fair. ○ The real difference was in the design interviews, lots of follow-ups, real curiosity about my decisions. ○ In-person Hiring Manager round checked for real fit and long-term vision. ○ You can sense when a company genuinely wants to know how you think. Rest 2 are in the comments… Job search is less like flipping a coin, and more like running a marathon with hurdles, some you clear, some you crash into, but you have to keep moving. The more finish lines you cross, the higher your chances of success. Every interview teaches you something. Eventually, persistence beats luck. Good luck, see you on the other side.

Most developers prepare for React interviews. But they forget the part that actually breaks real apps: async JavaScript. I’ve seen engineers who can build a pixel-perfect UI… …but freeze the moment you ask: “How would you stop 50 API calls from firing at once?” So I put together 5 async + architecture interview questions every frontend/fullstack dev should master. And the best part? Each one on IOCombats has: ✔️ A detailed explanation ✔️ Real implementation ✔️ A video walkthrough ✔️ A real-world use case ✔️ Common pitfalls interviewers look for Let’s go 👇 1) How do you control Promise concurrency in JavaScript? Most apps break at scale because they fire everything in parallel. Learn how to build: - async queues - batching - concurrency-limited fetchers This pattern is a lifesaver when you’re syncing data, uploading large sets, or hitting rate-limited APIs. Check here: https://lnkd.in/dbqeQRA8 2) How do you implement retry logic with exponential backoff? Network isn’t reliable. Your UI can be. Understanding backoff = avoiding UI failures during: - spotty connections - server hiccups - temporary timeouts And yes — interviewers love asking this because it separates copy-paste devs from system thinkers. Check here: https://lnkd.in/dk4qzBBx 3) Can you explain the event loop and execution order? Tasks. Microtasks. Macrotasks. If you don’t understand why promises run before timeouts, you’ll debug async bugs blindly. This is the foundation of every render cycle, every animation, every fetch, every state update. Check here: https://lnkd.in/d3g3ZDsj 4) How do you handle race conditions in async code? Ever clicked a button twice and got weird UI state? That’s a race condition. Learn patterns like: - request locking - cancel tokens - last-write-wins - shared state guards This is what senior-level frontend engineering actually looks like. Check here: https://lnkd.in/djFDSXjv 5) How do you safely handle token refresh when multiple calls fail at once? The classic bug: 5 parallel API calls → token expired → all 5 try to refresh → app crashes. The fix: A shared refresh promise, queued requests, and a safe retry pipeline. If you can design this, you’re already thinking like a backend + frontend hybrid. Check here: https://lnkd.in/dsn_FGtf These aren’t just “interview” questions. They are the patterns real production systems depend on. 👉 Explore the full breakdowns, implementations, and videos here Follow Ghazi Khan & iocombats for frontend/full-stack development, UI challenges, and jobs-related content.

In the last 15 years, I’ve interviewed at Google, Microsoft, Paytm, Amazon, and dozens of startups.  And no matter the company, the interview pattern rarely changes.  Here’s what to expect in 99% of product-based company interviews:   1. Data Structures & Algorithms (DSA)   Time: 45-60 minutes  What happens:   - Solve 1-2 DSA problems within the time limit.   - Write optimal, bug-free code that actually runs.   - Explain time & space complexity for every approach.   - Be prepared to handle edge cases, one miss can cost you.  DSA is usually the first filter. If you fail here, you don’t move forward.   2. System Design / High-Level Design (HLD)  Time: 60-90 minutes  What happens:   - You get an open-ended system design problem.   - Explain the architecture, database modeling, and API contracts.   - Think about scalability, performance, and fault tolerance.   - No coding, just whiteboarding & deep technical discussions.  There’s no single correct answer, what matters is how you think and justify your design.   3. Low-Level Design (LLD)  Time: 60-90 minutes  What happens:   - You get a generic feature to design - (like a parking lot system, ATM, or rate limiter).   - Define classes, attributes, and interactions.   - Follow SOLID principles and avoid redundant data.   - Sometimes, you’ll need to write actual code based on the discussion.  Good design choices can make or break your interview.   4. Machine Coding Round (MC)  Time: 90-180 minutes  What happens:   - Build a working solution for a given problem, this isn’t about theory anymore.   - Write executable, maintainable code for at least one core functionality.   - Follow best practices, clean code, SOLID, design patterns, error handling.   - Your code should be flexible enough for modifications (they might ask you to extend functionality).  5. Managerial Discussion   Time: 45-60 minutes  What happens:   - Deep dive into your past projects, expect follow-up questions.   - How did you solve challenges? What was your impact?   - Situational questions (answered best with the STAR method).   - You’re evaluated on ownership, leadership, and decision-making.  This round is not just about tech, it’s about how you work and think.   6. Cultural Fit Round   Time: 30-45 minutes  What happens:   - How well do you align with the company’s values & culture?   - Expect behavioral questions (e.g., “Tell me about a time you handled conflict”).   - Be honest, don’t make up stories to fit the values.  You can clear every technical round and still get rejected here.     Also, Some companies include:   - Concurrency discussions (how to handle multi-threading & parallelism).   - Pair programming (coding in real-time with an interviewer).   - Take-home assignments (especially in startups).  But for most product-based companies, these six rounds are the standard.  

Today, I witnessed my team lead interviewing a Full-Stack Web Developer with 2 years of experience, and I observed some interesting insights. The interview started with basic technical questions, which the candidate answered well. Then, my team lead gave him a coding task: 👉 "Write a function that removes duplicate values from a nested array while preserving its structure (PHP)." The candidate struggled and couldn’t solve it. So, my lead gave him another task: 👉 "Write a function that groups an array of associative arrays based on a specific key." Again, he couldn’t solve it. At this point, he admitted: "I don’t always have syntax and logic rules memorized, as I usually rely on resources like Stack Overflow and ChatGPT. Could you assign me a real-world task instead?" Here,I decided to step in. Since I was working on WooCommerce project, I gave him this challenge: 💡 "Implement a functionality where a logged-in user gets a 15% discount if they place two orders in a single day." We allowed him to use Google, ChatGPT, or any other resources. To our surprise, within 1.5 hour, he understood WooCommerce functionality, analyzed the existing code, and successfully implemented the feature. ✨ We ended up hiring him! ✨ Key Takeaway Many traditional interview techniques overemphasize logical puzzles and syntax-heavy questions, yet modern developers approach problem-solving differently. Rather than memorizing solutions, they adapt, learn, and implement on the spot using the tools and resources available to them. 💡 Instead of testing how well candidates remember syntax, we should focus on how effectively they apply problem-solving skills to practical challenges. What’s your take on this? Let’s discuss in the comments! 👇 #HiringTechTalent #TechCommunity #WhatDoYouThink

80% of Candidates Get Rejected in the First 10 Minutes. Here’s why: - You know HTML, CSS, and JavaScript - You’re comfortable with React, Vue, and Angular - You’ve used Redux, Tailwind CSS, and GraphQL. 𝗕𝘂𝘁 𝘁𝗵𝗲𝗻 𝘁𝗵𝗲 𝗶𝗻𝘁𝗲𝗿𝘃𝗶𝗲𝘄𝗲𝗿 𝗵𝗶𝘁𝘀 𝘆𝗼𝘂 𝘄𝗶𝘁𝗵 𝘁𝗵𝗲 𝗯𝗶𝗴 𝗼𝗻𝗲: “Tell me about a complex UI component you built in production and how you optimized its performance.” And suddenly, your resume isn’t enough. 𝗥𝗲𝗮𝗹 𝘁𝗮𝗹𝗸: Most candidates get filtered out, not because they don’t know the tools, but because they can’t explain how they used them in real-world scenarios. Here are 10 real-time, real-world questions to help you go from: ❌ I studied this on YouTube to ✅ I’ve solved this in production 𝟭. 𝗛𝗼𝘄 𝗱𝗼 𝘆𝗼𝘂 𝗱𝗲𝘀𝗶𝗴𝗻 𝗮 𝘀𝗰𝗮𝗹𝗮𝗯𝗹𝗲, 𝗿𝗲𝘂𝘀𝗮𝗯𝗹𝗲 𝗰𝗼𝗺𝗽𝗼𝗻𝗲𝗻𝘁 𝗹𝗶𝗯𝗿𝗮𝗿𝘆 𝗳𝗼𝗿 𝗮 𝗹𝗮𝗿𝗴𝗲 𝘄𝗲𝗯 𝗮𝗽𝗽𝗹𝗶𝗰𝗮𝘁𝗶𝗼𝗻? → Talk about design patterns, atomic design, and Storybook for isolated component testing. 𝟮. 𝗛𝗼𝘄 𝗱𝗼 𝘆𝗼𝘂 𝗲𝗻𝘀𝘂𝗿𝗲 𝗿𝗲𝘀𝗽𝗼𝗻𝘀𝗶𝘃𝗲𝗻𝗲𝘀𝘀 𝗶𝗻 𝘆𝗼𝘂𝗿 𝗮𝗽𝗽𝗹𝗶𝗰𝗮𝘁𝗶𝗼𝗻 𝗮𝗰𝗿𝗼𝘀𝘀 𝗱𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝘁 𝗱𝗲𝘃𝗶𝗰𝗲𝘀? → Use of Flexbox, Grid, CSS media queries, and tools like CSS-in-JS (Styled Components, Emotion). 𝟯. 𝗛𝗼𝘄 𝗱𝗼 𝘆𝗼𝘂 𝗶𝗺𝗽𝗹𝗲𝗺𝗲𝗻𝘁 𝗮𝗻𝗱 𝗼𝗽𝘁𝗶𝗺𝗶𝘇𝗲 𝗮 𝗨𝗜 𝗰𝗼𝗺𝗽𝗼𝗻𝗲𝗻𝘁 𝗹𝗶𝗸𝗲 𝗮 𝗺𝗼𝗱𝗮𝗹 𝗼𝗿 𝗮 𝗱𝗿𝗼𝗽𝗱𝗼𝘄𝗻? → Explain event delegation, useRef, and the importance of closing events and ESC key press handling. 𝟰. 𝗛𝗼𝘄 𝗱𝗼 𝘆𝗼𝘂 𝗮𝗽𝗽𝗿𝗼𝗮𝗰𝗵 𝗺𝗮𝗻𝗮𝗴𝗶𝗻𝗴 𝘀𝘁𝗮𝘁𝗲 𝗶𝗻 𝗰𝗼𝗺𝗽𝗹𝗲𝘅 𝗥𝗲𝗮𝗰𝘁 𝗮𝗽𝗽𝘀? → Explain Redux or Recoil, useReducer, Context API, and when you’d use each based on complexity. 𝟱. 𝗪𝗵𝗮𝘁’𝘀 𝘆𝗼𝘂𝗿 𝗮𝗽𝗽𝗿𝗼𝗮𝗰𝗵 𝘁𝗼 𝗲𝗿𝗿𝗼𝗿 𝗯𝗼𝘂𝗻𝗱𝗮𝗿𝗶𝗲𝘀 𝗮𝗻𝗱 𝗵𝗮𝗻𝗱𝗹𝗶𝗻𝗴 𝘂𝗻𝗲𝘅𝗽𝗲𝗰𝘁𝗲𝗱 𝗲𝗿𝗿𝗼𝗿𝘀 𝗶𝗻 𝗥𝗲𝗮𝗰𝘁? → Explain React error boundaries, logging with Sentry, and graceful error handling in UI. 𝟲. 𝗛𝗼𝘄 𝗱𝗼 𝘆𝗼𝘂 𝗵𝗮𝗻𝗱𝗹𝗲 𝗿𝗼𝘂𝘁𝗶𝗻𝗴 𝗶𝗻 𝘀𝗶𝗻𝗴𝗹𝗲-𝗽𝗮𝗴𝗲 𝗮𝗽𝗽𝗹𝗶𝗰𝗮𝘁𝗶𝗼𝗻𝘀? → Discuss React Router, dynamic routing, nested routes, and lazy loading of routes. 𝟳. 𝗛𝗼𝘄 𝗱𝗼 𝘆𝗼𝘂 𝗲𝗻𝘀𝘂𝗿𝗲 𝗮𝗰𝗰𝗲𝘀𝘀𝗶𝗯𝗶𝗹𝗶𝘁𝘆 𝗶𝗻 𝘆𝗼𝘂𝗿 𝘄𝗲𝗯 𝗮𝗽𝗽𝗹𝗶𝗰𝗮𝘁𝗶𝗼𝗻𝘀? → Talk about ARIA roles, semantic HTML, keyboard navigation, and ensuring screen reader compatibility. 𝟴. 𝗛𝗼𝘄 𝗱𝗼 𝘆𝗼𝘂 𝗵𝗮𝗻𝗱𝗹𝗲 𝗳𝗼𝗿𝗺 𝘃𝗮𝗹𝗶𝗱𝗮𝘁𝗶𝗼𝗻 𝗶𝗻 𝗮 𝗥𝗲𝗮𝗰𝘁 𝗮𝗽𝗽? → Discuss Yup, React Hook Form, and server-side validation with form error feedback. 𝟵. 𝗛𝗼𝘄 𝗱𝗼 𝘆𝗼𝘂 𝗼𝗽𝘁𝗶𝗺𝗶𝘇𝗲 𝗮𝗻 𝗮𝗽𝗽𝗹𝗶𝗰𝗮𝘁𝗶𝗼𝗻 𝗳𝗼𝗿 𝗵𝗶𝗴𝗵 𝗶𝗻𝘁𝗲𝗿𝗮𝗰𝘁𝗶𝘃𝗶𝘁𝘆 (𝗲.𝗴., 𝗰𝗼𝗺𝗽𝗹𝗲𝘅 𝗳𝗼𝗿𝗺𝘀 𝗼𝗿 𝗿𝗲𝗮𝗹-𝘁𝗶𝗺𝗲 𝘂𝗽𝗱𝗮𝘁𝗲𝘀)? → Talk about debouncing, throttling, and WebSockets for real-time updates, and form libraries like Formik or React Hook Form.