Photo Sharing App, Global Launch

A two-person team is launching a photo sharing app worldwide next month. The front end is a static single-page application; there is no server-rendered HTML. Photos are uploaded by signed-in users, stored as original files, and served to viewers in Tokyo, London and São Paulo with as little latency as possible. Photo metadata — owner, caption, timestamp, tag list — is only ever read by a single key lookup or a query on the owner, never joined across tables, and read volume is expected to be a hundred times write volume. Users sign up with an email address and password. The team has no operations engineer and will not accept anything they have to patch or capacity-plan.