System designMediumsd-g538

Subject Team file shareLevel Entry–Mid~35 minCommon in Security · Storage & CDN interviewsIndustries Software development, Technology

Question

Design a simple file-sharing service for a team. A member uploads a file (up to ~100 MB), gets a shareable link, and other members can download it; some files are private to the uploader and some are shared with the whole team. Storage should be durable and the app server shouldn't be a bottleneck for large transfers. Cover where files live, the data model, and how downloads and access control work.

What a strong answer looks like

Clarify scale and constraints first. Propose a clean component breakdown, then go deep on the hard parts — data model, bottlenecks, consistency, failure modes — and name the trade-offs you are making.

Learn the concepts

Narrate your design

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Run or narrate your approach, then ask the coach.