Coinbase Interview Experiences

15 results

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  Mempool Block Packing and CPFP Phone ScreenCoinbase · Software Engineer · Technical Screen · Oct 2026

  In progress

  It was the problem about picking transactions from a mempool to pack into a block. I hadn't really touched this area before, so I was a bit lost when I first read the problem. Part one gives an unsorted array of transactions, each with an id, fee, and size. The block capacity is fixed at 100. You pick some transactions to put in, the total size can't go over, and you want to collect as much fee a…

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  Four Onsite Rounds, Mostly Production Code Not LeetCodeCoinbase · Software Engineer · Onsite · May 2026

  This company's interview format is pretty different from everywhere else, so it's worth writing up on its own. Of the four rounds, only one was a traditional coding round in the usual sense — the rest were all "here's a small requirement, write code that could ship to production." They use their own online environment, where you can run tests and also look things up in the docs. So pure template…

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  Mempool Block-Mining Problem in the First Technical RoundCoinbase · Software Engineer · Technical Screen · May 2026

  A former coworker referred me, and HR contacted me about three weeks later. The first round was technical. Part one Cryptocurrency "mining" is the operation where a "miner" places "transactions" in a candidate "block". Each block has a fixed size B = 100. At any point in time there is a set of transactions available for mining in an unordered array called the mempool. A transaction can be describ…

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  Three OAs, a Block-Mining Coding Round, and Two AI-Assisted RoundsCoinbase · Software Engineer · Onsite · Apr 2026

  I heard Coinbase had layoffs today. Not sure how that'll affect hiring. Sigh, hope everyone's okay. The people I dealt with, including HR, were all really nice. Sharing my previous interview experience — the whole process. HR reached out asking if I wanted to interview with Coinbase (I'd applied 4 years ago but never went further in the process — they might still have had my info), so I went ahea…

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  Rejected After Onsite Over a Debugging NitpickCoinbase · Software Engineer · Onsite · Mar 2026

  Rejected

  Round 1: crypto order system, pretty similar to other write-ups already on the forum. I had to parse the input myself and write my own test cases. I got to level 2 — after I finished the tests, the output had no issues, but I wasn't given level 3. Round 2: the "generate NFT" question, also already posted on the forum. Also had to define and parse the input myself — I used JSON. I finished the fir…

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  Four Onsite Rounds, Rejected on System DesignCoinbase · Frontend Engineer · Senior+ · Onsite · Jan 2026

  Rejected

  I interviewed in March. I couldn't find a virtual onsite interview writeup for Coinbase Frontend Staff level on the forum. There were four rounds total. The questions themselves weren't that hard, but the bar was high. Tech Execution: Write a dropdown component. I'd suggest looking at a UI library's props beforehand, something like Ant Design. In this round you need to pay attention to reusable d…

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  A Coding-Heavy OA on the Cloud Storage ProblemCoinbase · Software Engineer · Online Assessment · Dec 2025

  I just finished Coinbase's OA. Overall I felt the problems weren't that hard, but there was a huge amount of code to write. If you hadn't prepared for it ahead of time, I don't think a normal person could finish the whole thing on first sight. This kind of test is honestly ridiculous, damn it — it really feels like they're just hunting for code monkeys. The problem was the cloud_storage one that'…

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  OA Full Marks, Then Rejected After the Virtual Onsite Coding RoundsCoinbase · Software Engineer · Onsite · Dec 2025

  Rejected

  OA was a geography question. I solved all 4 questions and got a perfect score. VO BQ — not like a normal BQ, more like a conversation. The interviewer dove deep into how I'd improve my projects. I don't know why, but after about 20 minutes he seemed to lose interest. He asked if I had any questions for him. After I asked, he went back to asking me about projects where I used a lot of different ap…

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  Two OAs and a 90-Minute Database Design Coding TestCoinbase · Software Engineer · Online Assessment · Nov 2025

  There were two OAs total. One was a personality test and an aptitude test. The personality test had over a hundred questions, and some of them repeat — be careful not to contradict yourself between them. The aptitude test was very tight on time: figure relations, quantitative relations, vocabulary fill-in-the-blank, that kind of thing. It's hard to finish in time, so just guess when you have to.…

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  Case Study, SQL, and a Live Python EDA RoundCoinbase · Data Scientist · Onsite · Oct 2025

  Part 1: case study plus SQL and Python. The case: an e-commerce company wants to send personalized emails to boost conversion rate. How do you measure success? It was basically the standard A/B test process — define the metrics, figure out how to calculate the sample size, all of that. There was a follow-up at the end: suppose we ran the experiment and saw conversion rate go up 20%, we thought it…

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  A 45-Minute Phone Screen Building a URL ShortenerCoinbase · Software Engineer · Technical Screen · Aug 2025

  In progress

  Sharing my backend phone screen with Coinbase. The process was a recruiter call, then the phone screen got scheduled about a week later, 45 minutes long. The question was to build the core logic of a URL shortener service, with the following requirements: Support generating short links Support automatically redirecting when a short link is visited Short links need an expiration time Concurrent ac…

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  Stuck on Debounce in the Autocomplete RoundCoinbase · Software Engineer · Technical Screen · Aug 2025

  Rejected

  Technical phone screen (1 round) It was a pure whiteboard-style coding round — I had to implement an autocomplete feature for an input box. Requirements: debounce, async fetch, and rendering the results. Follow-up: support keyboard navigation (up/down arrow keys to switch), highlight the selected item, and submit on Enter. I got stuck right at the debounce part — I couldn't get the event handler…

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  Crypto System Design, a Handwritten Iterator, and a Food Delivery Coding RoundCoinbase · Software Engineer · Onsite · Jul 2025

  Virtual onsite: System Design -> Pretty much the same as a version of this question that's been reported before. It's designing a crypto currency trading system, with a third-party exchange, using a sync API to interact with that third-party exchange. I had prepared something similar before. But the interview still had some stumbling — I felt my understanding was a bit off, and only figured it ou…

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  System Design, Two Coding Rounds, and a PIP I Didn't Mention to the RecruiterCoinbase · Software Engineer · Onsite · Jul 2025

  HR: Basically just chatted about my general situation. But I didn't tell the recruiter that I'm no longer at Amazon — over the last year and a half I wasn't very proactive at my previous company, and I didn't really listen to my manager, and I got PIP'd in May. (Should I be more upfront with the recruiter about this? If I actually get an offer, will the company find out during the background chec…

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  SQL, A/B Test Design, and a BTC Volatility CaseCoinbase · Data Scientist · Senior+ · Onsite · Mar 2025

  Background: Bachelor's degree in China + Master's in the US, Statistics / Data track 3+ years of data analysis / risk-control experience (mostly finance-related) Applied for: Data Scientist – Risk / Product Analytics (remote) Overall Process HR Screen → SQL & Stats → Product Case → Hiring Manager → Team Fit The whole process took about 4 weeks. Not super fast, but the feedback at each stage was p…