Your question is Dropbox-like File System Design. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Design Dropbox (file storing and sharing)
Discuss an end-to-end design for storing files, synchronizing them across devices, sharing them with other users, and applying ML where it improves retrieval, organization, or abuse prevention. Clarify requirements, identify appropriate online and batch paths, estimate scale, and explain reliability, security, evaluation, and failure handling.