Design a CDN: the content delivery network system design walkthrough The request to design a CDN sounds like a one-liner — put the files closer to the users — and that one line hides the whole interview. A content delivery network system design is not a file server with extra machines; it is a globally distributed read-through cache where a request from a phone in Mumbai should be answered by a server a few milliseconds away instead of crossing an ocean to your origin, and where the ha...