System design, written out in full.
Most system design prep tells you what to say in the interview. These pages try to show how to think the system through, so you can say it in your own words.
Each problem is one long document: the requirements, the architecture, the deep dives an interviewer pushes on, the data model, the API, and how to pace the conversation. Read it the way you would talk it through, start to finish.
How to help
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Who writes it
Anubhav Sethi
Co-founder
SWE III at Google; previously Amazon (AWS), Walmart, and HiLabs. Lives in system design and large-scale backends. Cracked 100+ interviews with offers from Uber, Meta, Intuit, and Microsoft and has helped thousands of engineers do the same.
Dhananjay Aggarwal
Co-founder
DevRel at Keploy, building AI-driven API testing and working with LLM developer tools every day. SDE @SourceFuse. Writes system design breakdowns on Medium (@theshardedgate): the CAP theorem behind Instagram like counts, why a payment goes through only once, how celebrity posts fan out, and why JWT systems fail quietly at scale. OSS contributor at Microsoft and Grafana, and a LeetCode Guardian (top 0.68%).