Backfill immunity is proved by replay, not by a hand-picked case: a ten-year
Apple Health export (12772 writes) and a 30-day provider re-sync (58 writes)
must both emit zero events, while a fresh sleep night, workout and first
weight of the day emit exactly one each.
The provider-isolation guard walks the worker's static import graph and fails
if any provider client or resolver becomes reachable. It carries two positive
controls, so a broken entry path cannot make it pass against an empty graph.
The integration test covers what unit mocks cannot: the unique index, the
ON CONFLICT DO NOTHING claim, the losing side of ten concurrent claims, the
forward-only marker, ciphertext at rest, the delete cascade, and the
retention window.
Every ingest path in the product can now emit a typed, salience-classified
event into pg-boss, consumed by one worker that claims a durable per-day
reaction marker and fans out to the reaction surfaces.
The recency classifier runs at the seam, before anything is enqueued, so a
mass backfill — a multi-year Apple Health export, a provider re-sync, a
30-day catch-up — emits nothing at all. Non-salient writes are annotated and
dropped.
The worker makes no provider call by construction: it imports no provider
module, writes only markers, and enqueues nothing that is not budget-gated
downstream. Business refusals return a status rather than throwing, so a
refusal is never retried against a ceiling that will not move until the local
day rolls over.
Seams: sleep (one hook, inherited by all seven transports), workouts (the
batch route, the four provider syncs, the export importer), weight and blood
pressure (both measurement routes), labs (manual, OCR commit, document fact
commit).
The provider workout syncs could not previously tell a created row from an
updated one, so a re-sync of a recent session would have re-fired on every
poll; they now recover the distinction from the row the upsert already
returns.
Reaction lines are AES-256-GCM at rest, following the InsightNarrative
precedent, and the column is registered for key rotation. Markers are pruned
after 14 days by a daily maintenance job.
Marc-André Bombeck