migration

Execution map

Nine phases integrate the Nautilus kernel first, then add durable projections, browser delivery, proof, rollback, and cutover.

Question: What is the next safe unit of work?
Binding decision: Only one implementation feature is active; bounded research and review may run concurrently with exclusive outputs.
Owner input: The next active feature is created in the Tradingview target repo only after Phase 0 freezes evidence.

0Freezeobserve
1Skeletonbuild + gate
2QuestDBbuild + gate
3Redisbuild + gate
4Backfillbuild + gate
5Fanoutbuild + gate
6Frontendbuild + gate
7Cold tierbuild + gate
8Cutoverprove + release

rollback remains live through every phase

The phase sequence

Phase 0 freezes current behavior and exact Nautilus revision/features. Phase 1 composes the Nautilus runtime, browser/service contracts, projection ports, and CLI. Phase 2 proves the bounded QuestDB projection and ReplayCatalog. Phase 3 adds rebuildable Redis projections. Phase 4 proves lazy historical fill. Phase 5 proves multi-user fanout. Phase 6 converges the frontend. Phase 7 activates a cold tier only on evidence. Phase 8 shadows, canaries, cuts over, and eventually deletes.

Every phase names exclusive paths and prerequisites.
Every phase has exact mise/Task proof commands and retained evidence.
Every phase defines rollback, stop conditions, and done.

Evidencedocs/generated/databento-data-layer-execplan.md.

The first move is observation

The design does not authorize production backend mutation. Begin in an isolated Tradingview worktree, freeze the current contract, pin the Nautilus source and feature closure, characterize DBN-to-Nautilus semantics, and write the preserve/change/delete matrix before introducing the runtime composition.

Runtime code and tests outrank documentation for current behavior.
Unknowns that change correctness, security, cost, or irreversible state stop the phase.
After two failed approaches at one seam, reduce to a minimal comparison spike.

EvidenceExecPlan Phase 0 and stop/escalation rules.

Open the orchestration sourcesed -n '1,220p' docs/generated/databento-data-layer-execplan.md

The complete phase ownership and gate contract is available.