A clean-looking spreadsheet can still

A clean-looking spreadsheet can still hide a broken record trail.

For this synthetic cleanup concept, I used four small rows so every correction could be traced:

— 2026-07-03 and Jul 03 2026 resolve to one duplicate — Excel serial 46208 resolves to 2026-07-05 — the formula error is repaired without changing the valid rows — source count, removed duplicate, and normalized output reconcile in the QA ledger

The signature element is the checksum seam. It keeps the raw rows visibly connected to the normalized table, because cleanup should preserve provenance rather than replace messy data with an unexplained polished sheet.

This is self-initiated concept work built with plausible synthetic data, not a client result. It demonstrates a small, reviewable before/after workflow for spreadsheet cleanup and data-quality checks.

Case study: https://contra.com/p/E7q7lFF3-concept-traceable-spreadsheet-cleanup