LincPayandClaude Opus 5
8efd9fd6ed
The book held one snapshot per loan, so there was no history at all and nothing a model could learn from. Two routes now fill it, and the difference between them is stated rather than implied: generate synthetic monthly snapshots for the prototype, or backfill month-end extracts from the lender's core, which is the real path — every core can answer "what did the book look like at each month end last year", because it is the query behind their regulatory returns. LoanRecord.source is stamped at every write site: SEEDED, SEEDED_HISTORY, UPLOAD, or the connector profile code. Coverage reports three buckets — synthetic, real, and unknown provenance — and never folds unknown into real, because an unlabelled row is not evidence of a lender extract. With no real extract on the book it reports trainable:false and says why in words. Generation never overwrites an existing row, so a real extract survives a regeneration untouched, and purge removes only what was generated. The generator's arithmetic had to be got right and was not at first. Real DPD steps: pay and cure to zero, or miss and roll forward one instalment period. The first version drew the day-of-month slack per month, so consecutive months differed by anything from 1 to 59 days — a shape no loan book produces, and one that would have taught a model a transition matrix nothing real generates. The slack is now fixed per delinquency episode, since a due date does not move between two missed payments: an account 5 days down that misses again is 35 days down, not 12. For the run reaching the anchor it is derived from the anchor's own DPD, so the series joins today's number exactly rather than near it. DpdWalk is shared with the simulated adapters, which previously returned today's DPD for every requested date — a backfill through them would have been a flat line, which is exactly the shape that makes a training label useless and which a chart would have hidden. Verified against a running instance: 3,256 snapshots across 142 loans, 24 monthly extract dates spanning 2024-08 to 2026-07, 100% of enterprises now carrying history, every generated series rolling by exactly 30 — the only non-30 steps being joins to pre-existing rows the generator correctly refused to overwrite. A 6-month Finacle backfill pulled 264 rows and staged them for review. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>