The design seems nice and clean, and the primitives on the back-end are about the right level. I wrote something similar, with golang, as a replicated object-s

The design seems nice and clean, and the primitives on the back-end are about the right level. I wrote something similar, with golang, as a replicated object-storage system. Although I didn't call it S3 I nearly did: https://github.com/skx/sos/ https://github.com/skx/sos/ Obviously there is a difference between "object store" and "file store", but it isn't so bad. I have a similar replication scheme: * Each node knows the objects it hosts. * Each host can poll others to see what a node should have. * Missing blobs can be synced.