System designMediumsd-g254

Subject Upload pipelineLevel Mid–Senior~35 minCommon in Distributed systems interviewsIndustries Technology, Software development

Question

Design the upload + validation pipeline for a public user-generated image/video host (think Imgur) accepting anonymous and authenticated uploads at 20K uploads/sec. Uploads must be validated (real media of the claimed type, within size limits), screened for abuse (CSAM/NSFW/malware), and made available quickly, but a malicious user must not be able to exhaust storage, smuggle a non-media payload, or get illegal content served even for a moment. Design the ingest path, validation ordering, and abuse defenses.

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.