S3-compatible object storage

Design the object-storage API and metadata layer for an S3-compatible service used heavily for media: multipart uploads of multi-GB objects, strong read-after-write so a client that uploads then immediately reads gets the new bytes, range reads for video seeking, and integrity guarantees (a corrupted byte must be detectable). Design the API surface, how multipart upload finalizes consistently, and how reads see a coherent view under concurrent overwrites.