- Context
- A service-business bookkeeping workbook had outgrown Excel: twelve monthly tabs kept in sync by hand, manual transfer macros, and tax estimates based on guesswork instead of real IRS math. This one is my own product, built and shipped end to end.
- The work
- Designed and built a Next.js and Postgres web app from scratch: a single transactions ledger, bank reconciliation, P&L reporting, and a Tax Planner with real self-employment tax, QBI deduction, and safe-harbor quarterly payment calculations, verified line by line against IRS sources.
- Outcome
- The twelve-tab spreadsheet became one system with real validation, and a later tax-accuracy pass caught a stale QBI threshold and a missing law change before either reached a user.