Bug investigations, defect root-cause analyses, security audits, performance regressions, and zero-crash hardening patterns tracked across momo’s development.
5 object-level query parameters now return honest 501 NotImplemented instead of silently falling into GetObject/PutObject/DeleteObject.
16 bucket config subresources (versioning, ACL, policy, CORS, lifecycle, etc.) now return honest 501 NotImplemented instead of silently misrouting to ListObjects/GetObject.
S3 ListObjectsV2 XML serialization dropped from ~1000 allocations to 16 per op via inlined time formatting and a pre-allocated escape buffer.
A 76-deep audit (authed via Sentinel) surfaced CRLF injection, smuggling, traversal and path leaks — the pattern that forged momo’s security mindset.
External S3 clients like aws-cli don’t send momo headers — the server detects this and downgrades client-side replication modes to server-side alternatives, ensuring replication never silently drops.
Systematic defensive coding: nil-safety, numeric overflow guards, resource lifecycle discipline, panic recovery at every boundary, and concurrency safety under -race.