Prevent
Reduce the number and size of failures that can occur.
- Repository and runtime separation
- Tenant-aware authorization
- Least-privilege delivery identities
- Backward-compatible migrations
Resilience model
Design the whole failure loop.
Resilience is more than redundancy. Cinch treats prevention, detection, recovery, and retained learning as one system—and names where the proof is still incomplete.
Last verifiedAugust 10, 2026
ScopeCinch application and public-marketing repositories
PostureCurated public engineering snapshot
Failure loop
Four disciplines, designed together.
Controls are useful only when the recovery and learning paths can feed what the system prevents and detects next.
Detect
Measure behavior a user or dependent service would actually feel.
- Candidate readiness
- Public journey checks
- Private sync-to-web proof
- Release identity verification
Recover
Prefer explicit, bounded, rehearsable recovery paths.
- Immutable-image rollback
- Database restore procedure
- Replica rebuild
- Preserved browser drafts
Learn
Turn consequential tradeoffs and evidence gaps into durable system memory.
- ADRs
- Evidence registry
- Runbooks
- Tests and review dates
Failure domains
Availability is specific.
The current proof distinguishes a release-safe stateless web tier from the stateful services and external dependencies that have different recovery behavior.
Public marketingIndependent version + rollbackIsolated from product releases
Stateless webTwo-instance blue/green fleetReplacement exercised
Authoritative dataManaged primary + recovery controlsRestore path exercised
Real-time syncRebuildable, volume-backed singletonMulti-node availability planned
Client continuityRelease notice + preserved draftsWebSocket cutover proof pending
Approved resilience evidence
Every resilience claim names its proof boundary.
Approved records preserve the distinction between automated validation and production exercise.
Health-gated blue/green application releases
Application releases use a blue/green strategy. The complete replacement web fleet and fresh SBOM-backed image policy must pass before traffic is promoted, the prior image is retained as rollback evidence, and routine application releases leave the real-time sync service unchanged.
Why it matters
Health-gated promotion reduces release risk for authenticated customers while separating routine product delivery from maintenance on the stateful real-time sync tier.
Scope and limits
Releases on 2026-08-10 exercised healthy replacement Machines, immutable identity, public checks, the private Zero hop, and unchanged Zero. On 2026-08-11 refreshed vulnerability data blocked two candidates without an exception or promotion. Later, evidence-backed OpenSSL dispositions yielded zero blocked findings; source 70e27f0ffa484fc0964f0672fc08a567d058adb0 passed the same gate, promoted two healthy Machines, passed all twelve public checks, and left Zero unchanged. Active-session continuity remains an evidence gap, so zero-interruption wording is not approved.
Next resilience proof
Scale the stateful boundary only after staging earns it.
The planned synchronization topology separates replication management from multiple disposable view syncers. It remains a roadmap item until loss, reconnect, rehydration, lag, queued writes, rolling replacement, and rollback are exercised in a production-like environment.
single-node lossbounded reconnectno acknowledged-write lossrolling replacementreplica rebuild
Next chapter