Code Room
System designHard
Question
Design the file-sync engine for a collaborative storage product where the same folder is shared across many users and devices that frequently go offline and reconnect. A device that's been offline for a week reconnects with hundreds of local edits while others have also changed the same files. Design how clients learn what changed, how you detect and resolve conflicts, and how you keep sync convergent and bandwidth-cheap without scanning everything on every reconnect.
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
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Run or narrate your approach, then ask the coach.