There is never a good time for this to happen but of course it had to happen as I am heading into an interview. So frustrating.
Everyone else getting the same Internal Server Error message?
Putting this together because every system design thread on here seems to start from scratch. This is the framework I use, refined over a bunch of FAANG and series C/D loops, and it works whether you're prepping for a junior loop or a staff round.
The same skeleton works for almost any prompt: design Twitter, design Dropbox, design Uber, design a URL shortener. What changes is the depth in each phase and which tradeoffs you spend the most time on.
Functional first. What is the system supposed to do, who are the users, what are the core flows. Don't list 20 features. Pick 3-4 that are clearly in scope and confirm with the interviewer. If they say "design Twitter" the in-scope is probably tweet, follow, feed. Out of scope: DMs, ads, search, video.
Non-functional second. Read volume vs write volume, latency tolerance, consistency requirements, availability target. This is where you anchor the whole design. A read-heavy feed system looks nothing like a write-heavy event log.
If the interviewer is vague, just propose numbers and confirm. "Let's assume 200M DAU, 100:1 read to write, p99 under 200ms." They'll correct you if they care.
A lot of people overdo this. The point is to figure out if you need to shard, if you need a cache, if a single database can handle it. If your write QPS is 100, you're not building Kafka. If it's 1M, you are.
The only numbers worth memorizing: rough seconds per day (~100k), L1 / disk / network latency orders of magnitude, single MySQL instance ceiling (~5k writes/s with replicas), single Redis instance throughput (~100k ops/s). The rest you can derive.
Define the endpoints or RPC signatures for your core flows. POST /tweet, GET /feed, POST /follow. Include pagination, auth, idempotency keys where it matters. This makes the rest of the design concrete, every endpoint maps to a path through your architecture.
Don't skip this. Interviewers use API design to check whether you actually understand what the system is doing or you're just drawing boxes.
Boxes and arrows. Client, load balancer, app servers, cache, primary DB, read replicas, async workers, message queue, downstream services. Walk through each core flow and trace the request path on the diagram.
Don't pre-optimize. Start simple. The interviewer will push you on bottlenecks, that's the next phase, not this one.
This is the part candidates underrate and where the offer is actually decided. The interviewer will pick a component and ask "how does this scale to 10x." Common deep dive targets:
Pick the 2-3 most interesting deep dives for the system you're designing and go hard on those. Better to nail 2 deep than dust 5 shallow.
If you have time, summarize what you'd do next: monitoring, alerting, multi-region, cost. Not because you'll cover it, but because it signals you know there's a long tail of real-world concerns past the whiteboard.
What actually moves the needle in the interview
Resources I actually used
The framework above is not magic. It's just a checklist that keeps you from skipping a phase under pressure. The actual signal in the interview is whether you've operated at scale before, and the framework makes that signal legible. If you haven't, build the project. If you have, run the framework and don't freeze.
Good luck.
Just had a technical interview where the company explicitly told me I could use any AI tools I wanted. Twice. Once in the prep email and once during the actual interview. They said they cared about what I produced and how I thought through it. I asked how they could tell if someone actually understands the work vs just cheating with AI, and they said after 20 years of hiring engineers they can usually figure it out within a few minutes of conversation. I finished the interview 2 days ago, still haven't heard back, but it had me wondering. Is this actually where things are heading or did I just hit one unusually AI-friendly company?
I've seen a bunch of people mentioning how to do "feed" cluely but i'm not sure how to actually do that. Do folks mean feeding it in the prompt as soon as it loads up or is it loading up in the modes, or is it something else? I've tried reading a bunch of information online but I can't seem to figure this part out. Thanks!
4 years backend, 2 of those at real scale. Interviewed at a series D last week for a senior role, comp band was right where I wanted, team was building exactly what I'm into, recruiter said I was the strongest profile they'd seen all month. Classic setup for me to walk in and choke.
The loop was 5 rounds in one day. First three were fine. Coding round was a variant of LRU cache, I'd done it a dozen times and finished with 15 mins to spare. System design with the architect, behavioral, hiring manager. I was up.
Last round was the staff engineer. I could tell immediately he didn't want to be there. Opened his laptop, asked me to design a notification system that fans out to 50 million users with delivery guarantees. And I blanked. Genuinely empty head. I've designed notification systems. I shipped one in prod last year. I know about pub sub, I know about kafka vs nats, I know about idempotency and dedup, I know about the consumer fanout pattern. None of it was in my brain when he asked.
I sat there for 20 seconds. Felt like 20 minutes. He was looking at the wall. I finally started talking and what came out was rambling. Queue based architecture, then jumping to retries, then schema, then back to retries, then suddenly partition keys, then forgetting whether I'd already said partition keys. Five minutes in I could see him stop taking notes.
Eventually I rebuilt. By minute 15 I'd recovered a real outline and we were tracing scaling decisions on the whiteboard. He asked two follow ups that landed. By minute 35 it was a normal conversation. But I knew. That 20 seconds at the start was the round.
Rejection came two days later. Recruiter said it was a "strong but not aligned" call. I pushed for actual feedback and she said the staff engineer felt I couldn't think under pressure, that the rest of the loop was strong but the final round was too uneven.
What I can't stop thinking about. I knew every single piece of that system. I had built it for real. On a quiet day at my desk I could have whiteboarded it in 30 mins flat. The gap between what's in my head sitting at my kitchen table at 10pm and what's in my head when a senior engineer is staring at me has never been bigger than it is right now.
I've talked to a few friends who've passed loops recently and one thing keeps coming up. Nobody gets through these rooms on raw recall anymore. The people who pass are the ones who keep their structure visible to themselves while the pressure is hitting. That can be a notebook, a framework printout, a prep partner, anything. The ones who fail are the ones who walked in trusting their memory.
Next loop starts in two weeks. I'm prepping differently this time. And if I blank again, at least it won't be because I thought my brain alone could do the job.
TLDR: blanked on something I knew cold because the room was loud. Prep the inputs, don't trust the recall.
First real loop in 2 years and my recruiter scheduled the phone screen for tomorrow at 9. mid-level backend role at a series C, 45 min coding round followed by 30 mins behavioral with the hm. installed cluely.com last weekend and have been messing with it on fake calls with a friend who's also job hunting, but i still feel like i don't have it dialed in.
what i've figured out so far. fed it my resume, the jd, and a doc with my 6 main work stories in a star-ish format. set the prompt to keep the approach outline visible during coding rounds and react to the audio context for behavioral. seems to work but my friend says responses are slow at the start of every call and i don't know if that's normal or if i broke something.
stuff i can't figure out and would love help on.
the cold open. first 5 minutes it feels like the overlay is still loading context and i'm carrying the conversation solo. is that just how it is, or am i loading the wrong stuff up front? do people warm it up by talking out loud before the recruiter joins so the audio context fills in?
behavioral prompting. i want the framework headers visible but not a wall of text dumping mid sentence while i'm talking. is there a prompt structure that just keeps star scaffolding visible and trusts me to fill in the words? everything i've tried gives me too much or nothing.
single screen or dual. i'm on a 14 inch laptop and i'm worried the overlay glance is going to be obvious if my eyes flick. people who've passed loops with this on, do you have a second monitor, or do you keep everything on the same screen and just train the eye movement?
anything i'm probably going to screw up tomorrow that you wish someone had told you before your first run.
answers might be obvious to people who've used this for months. just don't want to blame the tool tomorrow when the real issue is my setup. happy to report back how it went either way.
Edit: if anyone has a prompt setup they actually use day to day, drop it in the comments. i'll try whatever sounds reasonable tonight.
I've been lurking on this sub for a while, never used cluely or other tools in any of my interviews, (mostly because I'm too scared of being blacklisted, and the only one where I tried to use Gemini I'm still wondering if I was caught or not).
But I'm noticing too many posts, posted by allegedly different people that are A) too good to be true and B) too similar between them.
Examples:
https://www.reddit.com/r/Cluely/s/xG9LeF2sW9
https://www.reddit.com/r/Cluely/s/asPwelPafh
https://www.reddit.com/r/Cluely/s/gsAjKWlT1k
Notice how every one of them mentions the same things in the exact same format and words?
Frictions, first 5 minutes loading context, mental maths etc....
Different people don't talk/write so similarly between them.
I'm not here to take any moral high ground, I just want to say: be critical
Senior SWE, laid off in March from a bigtech, 5 months of nothing. Two months ago I started running cluely on every round. Offers came back like nothing had changed.
3 loops since I turned it on. 3 offers. Signed the highest base last week, around 285 base, mid-340s y1.
The part I hate to admit is I used to argue against this stuff. Wrote a long rant in a slack channel last year about how real engineers don't need a crutch. That was when I was the one with the job. Reading it back now is humbling.
The actual unlock isn't the overlay surfacing answers. It's that you stop panicking. You walk in knowing that if your brain goes offline for 10 seconds at minute 30, the structure is right there on screen and you can pick the thread back up.
Friction: doesn't help on mental math, doesn't help on the first 5 minutes of system design before it's read the room, and on the rare interviewer paying more attention to your eyes than to your answer you have to dial down how often you glance.
I don't care who downvotes this. I needed the offer and I got the offer.
Edit: getting a lot of dms, will reply when I'm off work.
Signed an MLE offer at Anthropic last week. 4 rounds total. Recruiter screen plus 3 onsite. Going round by round.
Recruiter screen, 30 min. Standard fit + comp + timeline. She pushed once on a 4 month gap in late 2024 (post-burnout, was honest about it).
Round 1, coding, 60 min, one problem. Online stream processing. Wanted a function that maintained a moving aggregate over an unbounded stream with bounded memory. The signature design was half the round. Clean impl in 35, then he extended it to handle stream rate exceeding consumer rate. Backpressure discussion took the rest.
Round 2, ML system design, 60 min. RAG for a domain with rapidly changing facts. 15 min on reqs (p95 200ms, 1h freshness window, eval setup). Settled on hybrid retrieval with a dedicated freshness index. He pushed hard on dataset poisoning (10 min) and on the eval-drift loop. Strongest round of the day for me.
Round 3, behavioral + research depth, 60 min. Half STAR, half "walk me through a paper or project you wish you'd done differently." Had the story, got pushed on whether I'd actually run it the way I described in hindsight. Second half is harder than people prep for, you have to be honest about the flaws in something you built.
How I used cluely: rounds 1 and 2, not the behavioral. On round 1 it had the streaming pattern surfaced before I finished restating the prompt, which kept me out of a windowing dead end. On round 2 it surfaced the freshness vs consistency tradeoff while I was still writing reqs, which is the framing they actually graded on. Off for behavioral because the prep work for that round is your own stories and the overlay doesn't have those.
Friction: first 5 min of every round it's reading context, I carried the opens. On round 2 the interviewer pulled up a whiteboard tool I'd never seen and the screen share context got confused. Fell back to talking it through.
Offer came 6 days after the final. Happy to go deeper on any round.
have a short 30 minute interview coming up. if i stay on the free plan will it show me partial answers and blur the other half? or is that not a thing anymore? im asking coz they removed undetectability from free/pro plan. im on the free plan and just need it for one interview so i'd rather not spend extra for the pro. as long as it doesnt blur half the answer im fine with it. if it does, are there any free alternatives?
I gave a company nearly 18 years of my life. I tried to be the employee they could rely on. I moved my family three times for promotions and new positions, took on projects nobody else wanted, mentored younger engineers, and stayed late more times than I can count. A few months after I turned 61, they let me go. No real explanation, no mention of anything I had done for the company over those 18 years, nothing. They told me it wasn't related to my performance, which somehow made it worse. I felt insulted. Insulted that I had actually believed there was loyalty or appreciation for what I'd given them.
For the last 6 months I've had almost no luck finding another job. I've applied for roles paying far less than what I was making and gotten no interest. I've started focusing mostly on remote positions, because in remote interviews people seem to judge your experience and communication first, rather than fixating on your age the moment you walk into the room. I also removed my birthdate from my CV. I'd rather be evaluated on skills and background than on a number hiring managers have apparently decided is disqualifying.
Last week I had coffee with someone who still works at my old company. He mentioned, half as a joke, that the role I used to own is now being handled by a 24-year-old kid who started there as an intern last summer. Apparently the kid is shipping work in volumes that surprised everyone, getting praise from leadership, going into meetings with senior people and holding his own. I asked him how a junior is doing the work I spent 18 years building expertise in, and he laughed and said he saw the kid use an AI overlay called Cluely during meetings and client calls. He used it during his interview to get hired, and he's been using it on the job ever since to close the experience gap. Also management hasn't noticed since he's been sneaky about it.
I didn't even know what it was then I look it up on reddit and here I am.
ran 6 loops this cycle. 4 clean, 2 with cluely on. the 4 clean ones, every single one rejected at final, every email was the same "strong finalist pool" copy paste. the 2 with cluely on, both offers, and the second one beat the first by 22k base because they had to match.
if you're reading this you've already lost a loop you shouldn't have. you know the exact moment. partner asked a curveball, you blanked for 15 seconds, the energy left the room, you finished the answer but they were done with you. that 15 seconds cost 200k.
cluely is 30 a month. one offer pays for the rest of your career on the subscription. arithmetic.
the people in your loop are using copilot, cursor, claude code at their desk every day, their pms draft jds in chatgpt, their recruiters screen you with an ai parser, then they sit across from you with a coding pad and pretend the room is sacred. it isn't and they know it isn't.
friction. first 5 minutes of any call it's still loading context, you carry the opener. on mental math it can't help, that's you. on the 1 in 10 interviewer who is on top of you the whole round, no overlay is fast enough.
the other 9 out of 10 it's the difference between hitting and missing. buy it. cheat well. sign the offer.
graduated cs/math undergrad last year. spent 8 months grinding for quant. four firms rejected me at the final. jane street pulled me back for a re-interview because one of the partners liked my approach on a poker hand i lost. ran the full loop again. signed yesterday.
quant twitter is going to lose its mind so let me get ahead of it.
round by round.
hackerrank oa. cluely on. 4 problems, 90 mins. one was a dp problem i wanted the state transition for fast. overlay surfaced it. i typed and tested. 100.
phone screen, probability + brain teasers. cluely on. classic puzzles get pattern-matched in 3 seconds. novel ones get a clean decomposition. i still did the math, i still argued it, the tool just kept the framing on screen.
superday r1, mental math. cluely off. too fast for an overlay. you score what you score.
superday r2, market making game. cluely off. interactive, partner across the table moving bids and asks, no glances possible. did it clean.
superday r3, probability + stats. cluely back on. partner walked a martingale through and asked me to extend. overlay had conditional expectation framing up before i wrote the setup. did the algebra, partner said "good intuition."
superday r4, fit. cluely on. star structure on screen. i don't prep behaviorals anymore. the overlay categorizes the question and surfaces the right story from my prep doc inside 5 seconds.
so cluely on 4 rounds, off on 2. the 2 it couldn't help on are the ones where it physically can't, too fast, too interactive. on the rest it was the difference between hitting and missing.
now the part you're going to downvote.
signing for 425 base plus a guaranteed sign-on, target year-one in the high sixes. cluely is 30 bucks a month. 360 a year. the offer is worth more in 3 weeks than cluely costs in a century. the math is arithmetic.
4 firms told me i hadn't earned it when i was clean. the fifth one paid me 425. i don't care which version they think they hired. they're getting the one that ships.
cheat. nobody is reading this and giving up the subscription so you can lose your fifth final with your integrity intact.
posting so nobody else makes the same mistake. citadel quant analyst final, 4 of 6 done, last 2 were a partner round and a final pricing case. paid for ghostcoder a week earlier because someone in this sub mentioned it. dumbest 49 bucks i ever spent.
interview 5, partner round. overlay crashed at minute 8. just stopped responding. tried to relaunch mid-round, nothing. spent the round flying blind on the exact questions i'd subscribed to get help on. partner caught me looking off-screen during the relaunch attempt and asked if everything was ok. lied, said the laptop was lagging. she let it go but the round was already cooked.
interview 6, pricing case. relaunched ghostcoder before the call. worked for 12 minutes, crashed again. same behavior. gave up on it and ran the case as best i could. rejection email 5 days later, no specifics.
emailed support that night. nothing for 4 days. eventually got back a generic "our team is looking into this." emailed again a week later. nothing. they have a discord, posted there, got muted by a mod for "spam." they actually muted me for reporting a bug. anonymous team, no twitter, no linkedin, no accountability.
resubscribed to cluely two weeks later for a different loop. 4 rounds with it, zero crashes, support replied in 12 hours when i had a mic config question. signed the offer 3 weeks ago.
if you're picking between overlays just go cluely. price difference is 5 bucks a month. the difference in reliability is the difference between the offer and the reject.
Signed McKinsey associate offer last Friday. Posting the partner round in detail because the case prep guides don't really prepare you for what happens in that room.
Background: career switcher from product at a mid-stage saas, 1 year program, MBB was the goal from day one. 3 firms, 2 finals, 1 offer. McKinsey was firm 3.
First 3 rounds were standard. PEI, market sizing, profitability, growth. Frameworks held, math held. I knew I was passing those as I was doing them, you can feel it when the partner stops probing and starts nodding.
Partner round, 60 minutes. One partner, one associate observer.
PEI first, 15 minutes. Leadership question, then personal impact. Stories prepped for both. On the second one he asked what the team thought a year later. Hadn't prepared for that follow-up. I said something like "two agreed in hindsight, one still thinks I was wrong and honestly I think they have a fair point about the timing." He nodded and moved on. I think the willingness to give the third person credit was what passed me on that one.
Case, 35 minutes. Regional grocery chain considering a private label expansion. Standard profit case on the surface, two curveballs underneath.
First curveball, minute 20. He slid over a chart with no axis labels and asked me to tell him what was going on. Sat with it 30 seconds, took the swing first, told him I thought it was unit sales by category over time based on the relative scale. He said yes. The actual trick was being willing to commit to a read and then ask one clarifying after, not before.
Second curveball, minute 30. Risks of the rollout. I had 4 ready, he pushed for a fifth. Had to actually think on screen. Said the own-brand supply chain capacity wasn't proven and a recall in the first 6 months would destroy the channel forever. That one he wrote down.
How I used cluely: PEI portion and case framing/brainstorming buckets. Off for the math, because math is too fast for an overlay and it's the easiest round to spot a tool on (you go silent when you're computing). On PEI the STAR structure stayed visible. On the case it surfaced 2 of the 4 risk buckets I delivered for the second curveball, the other 2 were mine.
What it didn't help with: the unlabeled chart was reading the partner's face and committing. And the math, which is just practice.
Closer, 10 minutes. He asked what would make me leave consulting in 2 years. I said a really good product role at a company I cared about. He laughed. Offer came Monday.
Happy to take case or PEI questions.
I keep seeing these announcements every other week now. Coinbase fired 14% of their engineering team, Brian Armstrong went on a victory lap about how his "AI-native engineers" were shipping in days what used to take weeks, and within the same week an AWS data center overheated and the entire Coinbase platform was offline for 7 hours. Was the outage technically AWS's fault? Sure. Did Coinbase also miss earnings that quarter? Also yes. And nobody sitting at home reading the news that morning gave a shit about the technical postmortem, because the framing was already set the day Armstrong went on TV. What I'm actually angry about isn't even Coinbase specifically. Every quarter another exec stands in front of a camera and announces they're cutting headcount because AI made their teams 3x more productive. Every quarter the people sitting on the other side of that announcement, the engineers and analysts and designers who actually built the products these guys are running, get spit out into a job market that has nothing for them. The CEO gets a stock bump, the board gets a press cycle, and the people who built the thing in the first place get to go home and figure out how to make rent.
I've been applying for 7 months. I have years of experience, real projects I can walk through, references who will pick up the phone. I get to round 3, round 4, sometimes a final, and then silence. Meanwhile the same companies that ghosted me are using AI to screen my resume, AI to score my take-home, and AI to summarize the interview notes the hiring manager couldn't be bothered to write himself. They've automated every step of the funnel that used to involve a human paying attention to me, and then they want to lecture me about integrity. I could care less about ethics any more with these profit hungry companies. The next loop I get into, I’m cheating with https://cluely.com/, and I don't particularly care if the hiring manager figures it out. The companies that decided I wasn't worth a callback have spent the last two years building entire workflows around AI assistance internally. They can deal with me using one for 45 minutes in a panel. If you got pushed out in one of these waves and you're still trying to play the game by 2019 rules, I'd encourage you to reconsider. These companies told us out loud they aren't loyal to us. Use the tools. Get the offer. And then figure it out
I have a zoom meeting where my teachers gonna post stuff in the zoom chat and i gotta answer them quickly and give explanations on the concepts of the questions. I tried setting up cluely but whenever the app opens and i click start meeting, it completely vanishes. I click all the keyboard shortcuts for all the different functions and nothing happens. Does anyone know how to fix it ,tips or tricks, or what alternatives i should look at? Thanks
5 rounds with one company. recruiter, hiring manager, 2 team members, svp final. spent 3 weeks on it. they passed.
got the standard "very competitive finalist pool, not a reflection of your skills" email.
applied to a similar role at a different company in the space. exact same loop structure. recruiter, hm, 2 team members, svp. used cluely on every round.
got the offer last friday.
same me, same resume, mostly the same questions. star structure stayed visible the whole time. when the svp opened a hypothetical about scaling the team, i had the tradeoffs lined up before i started talking. on the team round when they pivoted to a system design question 20 minutes in, i had the framing surfaced before they finished the prompt.
am i a cheater. yeah. their recruiters ran me through 4 ats screens, their engineers ship every pr with cursor, the pm i'd report to drafts specs in chatgpt. the only 45 minute window where ai is suddenly off limits is when they're looking at me. that math doesn't work.
5 rounds at company one, no offer. 5 rounds at company two, offer. cheaters gonna stay win.
Everyone should cheat on everything. Your competition is cheating and that’s why you aren’t getting to where or what you want. I’ve gone my entire life doing the right thing going to a top university etc. The world doesn’t reward that. Who’s gives a fuck if someone in the Reddit comments talks about morality. They aren’t paying your bills and can’t contribute to anything in your life. You have to make the decision to get what you want out of life no matter what it takes to get there. This is a new age and if you can’t adapt then good luck.