Use Claude to preserve Excel in a mobile budget app

The note author mo wanted to enter household expenses on a smartphone while retaining an established annual Excel workbook. Claude Code helped build a browser app with a database as the primary record and Excel as an export.

Matching totals initially concealed other errors. The regenerated workbook had changed row order, missing content, formulas replaced by values and lost formatting. mo asked for a cell-by-cell comparison tool, then changed the export method to update only modified rows inside a copy of the original workbook. Untouched workbook components were copied through instead of rebuilt.

Acceptance depended on three checks: an unchanged export matching the original bytes, comparisons after additions or edits, and monthly totals reconciled between the database and Excel. This also exposed a missed row in the author's old monthly summary.

Receipt photos became drafts that required confirmation before entering the ledger. Debugging showed that an unreadable result could mean the image path had not reached Claude at all. Orientation handling required further revisions, including comparing four rotated versions; a stale displayed image later proved to be the browser's problem. The working arrangement retained human checking at both spreadsheet export and receipt entry.

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Source: note.com · mo