Lambda Cross-Account S3 Write - file sync

A small program in one account drops files into another account’s storage by borrowing a visitor pass there, and a word stamped on that pass decides which folder it may touch.

Before you start. The Badge Machine - IRSA end to end left you one idea: a program that needs to get into somebody else’s space doesn’t have to carry a permanent key to it. It can call ahead and borrow a pass that works for about an hour, then dies on its own. The Locked Filing Cabinet - folder-level S3 access left you a second: one shared storage area can be split into per-team folders, with a single word on the request deciding which folder opens. Everything else, this lesson shows before it names.

frame: The Badge Machine - IRSA end to end · principle: Why So Many Boxes? - Identity vs Permission · prefixes: The Locked Filing Cabinet - folder-level S3 access