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Dropbox System Design
Visual Problem Diagram
Scenario
A user edits a 500 MB deck on a train while another laptop saves a different copy from the office. Hotel Wi-Fi drops halfway through a large upload. A shared folder sends thousands of change notifications at once. A Dropbox-style system must keep files durable, resume broken uploads, sync only what changed, and never silently overwrite someone else's work.
Design a cloud file sync product where users can upload files, edit them across devices, share folders, recover old versions, and keep working while offline. The hard part is not only storing bytes. The hard part is knowing which version is current, which chunks belong to that version, and what to do when two devices disagree.
Constraints
Constraints will be defined in the Requirements stage.
Stages ahead
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