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Interview Horror Stories
Tech interviews, DSA rounds, take homes and ghosting
Coding rounds, system design, take home assignments that took a week, recruiters who ghosted, offers that got pulled, and the occasional interview that went great. Prep resources and real questions welcome.
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16 posts
Created May 2026
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Moderated by Kunal Bhatia
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Pair up for 45 minute mock interviews: DSA, system design, behavioural, SQL. Swap roles halfway, post three lines of honest feedback. Use your own problems, never NDA ones.
The negotiation scripts that worked, the ones that didn't, rejections that hurt, and the celebrations when it went right
Showing 16 posts.
Posts in t/interview_horror
- 9 rounds cleared means the skill part is done. The rest is timing and freezes. Saturday mock still on?
Mock interview breakdown: she solved it and still got "no hire". Here is the scorecard.
Kunal and I have been doing free mock interviews on weekends this month. One of them taught me more than the others, so with the candidate's permission (and details changed) here is the full breakdown. She solved the problem. Her code was correct. In a real loop she would have got a "lean no hire". Let us see why. The question type A merge intervals variant. Medium difficulty. Nothing exotic. Minute by minute 0-3:…
- the "say done only after dry running your own example" rule. i lost a round last month by saying "done" and the interviewer immediately typed [] as the input. silence. 💀
- I was the interviewer on this one. The "defending instead of listening" at minute 18 is the one I see most. The follow-up is a gift and people treat it like an attack.
SEVENTH ROUND AND THEY HIRED INTERNALLY
ok. deep breath. let me write this properly. SDET role at a Pune product company. not my old company, a different one, good reviews, good team. i was so careful with this one. here is the loop: HR screen online test (java + SQL) automation framework design: playwright, API testing, how i'd structure test data, CI integration live DSA, two mediums hiring manager round director "culture fit" round "one final chat with…
- Asking about internal candidates upfront is a good lesson. I'm adding it to my own list. Sorry, Rahul.
System design primer: design a rate limiter, with real numbers
Most rate limiter answers I hear in mocks are one box on a diagram labelled "rate limiter" and then the candidate moves on. That box is the whole question. Let us do it properly, with numbers. Thanks to Kenji for reviewing the draft. 1. Requirements (spend 5 minutes here) Public API behind a gateway. 10 million daily active users. Limit: 100 requests per user per minute. Some endpoints (login, OTP) much stricter.…
- From the on-call side: whatever you build, log every 429 with the key and the rule that fired. The first incident will be a big customer behind one NAT IP getting throttled as "one user". Ask me how I know.
- Kenji, if you're comfortable, send the recruiter a short, factual note. Good companies want to know. I've removed people from interview panels for exactly this.
CF Expert but bombed my first real interview. interviewer said 'communication'. what does that even mean for a coding round?
ok so. codeforces expert (1680), ICPC regionals twice. first internship interview yesterday, dhaka product company, panel was remote from singapore. problem was a medium graph thing. had the idea in 2 min, coded it in 8, passed all their cases. feedback today: "strong problem solving, weak communication, no hire." bro WHAT. i solved it. faster than anyone they've probably seen. what do they want, a ted talk? also…
Accepted answer
Mahin, I'll be honest because I know you can take it. On Codeforces, a judge reads your code. In an interview, a human is scoring HOW you got there, because on the job your teammates have to follow your reasoning in design docs and code reviews. What "communication" means concretely on their rubric: 1. Restate the problem and ask 1-2 clarifying questions (directed? weighted? can it be disconnected?), even if you already know. 2. Say the brute force in one sentence, and why it's too slow. 3. Say the idea before coding: "multi-source BFS, because...". 4. Narrate lightly while coding. Not a TED talk, just signposts. 5. Dry run a small example before saying "done". Give the complexity without being asked. 6. Readable names, no macros. You're writing for a reader now, not a judge. Your speed is a huge asset. Slow down to 70% and spend the saved time on 1, 2, 3 and 5. You'll be a strong hire everywhere. And yes, I'm still saying LeetCode-style interviews are their own skill 😄 You can be much better than me at CF and still need this.- Very common with strong CP folks. You think in jumps, interviewers grade steps. Practise by recording yourself solving one problem a day out loud, 10 minutes. Painful to watch, very effective.
react + typescript interview questions from my last 11 rounds (and what they were actually testing)
day 22 of the hunt. 11 rounds at 6 companies so far: 4 machine coding, 3 DSA (easy to medium), 2 frontend system design, 2 behavioural. here's what came up in the frontend rounds, and what i think each question was really testing. 1. "why does this effect run twice?" react 18 strict mode runs effects twice in development, on purpose, to catch effects that don't clean up after themselves. they are testing whether you…
- This is exactly what I needed for our mock on Saturday. Number 2, the stale closure, I would have failed it. Thank you Sneha.
- the autocomplete machine coding round is everywhere in Mexico too. AbortController is the part 80% of people forget. great list
Read the constraints first: how I pick the pattern in under 2 minutes
Most people read the story in a problem and skip the constraints. The story is decoration. The constraints tell you the complexity you are allowed, and the complexity tells you the pattern. This is the routine I use, and the one I have been teaching in mocks for six years. Step 1: constraints → your budget Rough rule: a judge does about 10^8 simple operations per second in C++ or Java. So: n ≤ 20 : exponential is…
- constraints table is basically what every CF guy does without thinking. two corrections tho: n ≤ 500 can also take O(n² log n) comfortably, and 10^8/sec is for simple ops in C++. python is like 10^7 on a good day
- Coming back to DSA after a 6 year break, and this is the first cheat sheet that explains why and not only what. PFB my query (haha, old habits): is the prefix sum + hashmap approach expected from freshers or only experienced people? Thank you Nikhil sir.
- watched with my coffee. as a PM who sits in on interviews sometimes, yes, please talk to us. we can't grade what's inside your head
What I actually write in the interview feedback form (and what gets people rejected)
Candidates almost never see what happens after the interview. I've been a hiring manager for six years and have filled in some hundreds of these forms, so here is what is actually on it and what I write. The form Ours has five fields, and most companies I know use something similar: Problem solving Coding Communication Ownership and attitude (with a specific example required) Overall: Strong No / No / Yes / Strong…
- Love the Avvaiyar line. Hiring in embedded, I ask the same "why" questions about their final year project and it reveals everything in 5 minutes.
- Agree on requirements. I've been on both sides of maybe 200 of these. The candidates who fail usually start drawing boxes in minute two. The ones who pass ask how many submissions per second arrive when a contest starts, because that spike is the real problem in a LeetCode design.
Five months laid off. 431 applications. Here is the actual funnel.
I was laid off in February after nine years at a large tech company. I've kept a spreadsheet since day one, partly because I'm an engineer and partly because counting things is how I stay sane. People keep asking what the market actually looks like for a senior backend engineer right now, so here are the real numbers, February through July. The funnel Cold applications (career pages, job boards): 431. Any human…
- If you ever want to price a contracting rate, or an indie thing as a side runway, ping me. With your background you are underpricing yourself in your head right now, I can tell.
- python in a dsa round is a red flag tbh. interviewer thinks you cant handle real languages
Monotonic stack, explained with a queue at a chai stall
Problem: for every element in an array, find the first element to its right that is greater than it. If none, -1. Brute force: for each i, scan right until you find something bigger. O(n²). With n = 10^5 you are done for. The chai stall Imagine people standing in a line outside a chai stall, all looking to the right. Each person wants to know: who is the first person to my right who is taller than me? Walk along the…
- the dry run list is so helpful. I am QA not dev but I followed every step. thank you
Offer rescinded 6 days before joining. After I had already served my notice.
This happened three years ago and I still have the email saved in a folder called "never again". I was at a service company. Got an offer from a mid-size SaaS product company, 75% hike, my first product role. I negotiated my 90-day notice down to 60 with a partial buyout, served it, did the handover, had the farewell cake, collected the "all the best" emails. Six days before my joining date, at 7:40 pm, an email:…
- This is why I never fully trust an "offer" until the first salary hits. Freelancer brain maybe, but it has saved me
The take-home that took me a week and got ghosted
Yesterday I created this topic. Today I am writing the story that is the reason it exists. It is 1 am and I am still a little angry about it, two years later. Series B fintech. Recruiter call went well. Then the take-home arrived: "should take 4 to 6 hours". The brief: A payments reconciliation service with a REST API Unit and integration tests Dockerfile and docker-compose A README with design decisions "Bonus: a…
- series B fintech asking for docker + tests + ui for free. should have walked at the brief. thats on you tbh