Forward: Production Roadmap (R5–R11) and the Research Guide
After R1–R4: the P0 hardening done, the P1/P2 tracks (metrics, HA metadata, auth, secrets, S3 breadth) and the research reading guide that seeded it all.
Go
At-Rest Integrity: Verify-on-Read, Checksums, and GC
CAS keys make verify-on-read free: central verification, x-amz-checksum echo, tombstone GC, and corruption surfacing.
S3 Integrity Checksums: x-amz-checksum-*
x-amz-checksum-CRC32/SHA256 echo on PUT; integrity surfaced to clients so dirty bytes never masquerade as clean. Teaches: client-verifiable integrity, Bolt zero-allocation on read path, Sentinel honesty guarantee.
Adaptive Scaling: Gossip Fanout, Stream Chunks, Peer Quality
Three adaptive feedback loops: gossip fanout scales with cluster size, streaming chunk size adapts to cipher/memory, peer quality feeds quorum decisions.
Confidential Dedup via Threshold OPRF — and Auth Lockout
Threshold-OPRF lets E2EE cas blobs dedup without revealing content hashes — plus adaptive failed-auth backoff and lockout.
Scatter-Gather and Lease Consensus: Quorum Math
Scatter-gather lists across shard owners; leases with correct majority quorum — and the two nasty off-by-one/partition bugs found by audit.
S3 Multipart and Protocol Breadth: 501 Discipline
Multipart upload support plus a rigorous 501 strategy for unsupported S3 subresources — honest breadths over silent misbehavior.
⚡ Bolt: Zero-Allocation and Hot-Path Engineering
The Bolt mindset codified: no heap escapes in hashing/encoding, deadline amortization cuts SetDeadline ~98%, allocation hotspots hunted by profile. Teaches: zero-escape patterns, measurement contracts, trade-off posture.
S3 and Inbound TLS: HTTPS-by-Default Enforcement
The S3 gateway turned HTTPS-or-explicit-insecure into the default: no silent plaintext for the gateway or inbound tcp/quic.
S3 Auth: SigV4, Presigned URLs, and Key Decoupling
Query-string SigV4 for presigned URLs, mandatory X-Amz-Date freshness, and decoupling gateway access/secret keys from the native auth token.