Build · Level 5 · Build
Loan Model to App
A polished amortization app in twenty minutes, and its month-one interest is wrong — the reimplementation used actual over 365 where the workbook uses 30 over 360, and the chart looks superb either way. Build the discipline that makes a reimplementation trustworthy: freeze the verified logic and its test vectors first, keep the engine and the interface apart, and refuse to ship anything that does not match the workbook to the cent. Then migrate a model version cold, regenerating the vectors instead of nudging the engine until the chart looks right.
6 parts
Opens with Pro
$499 a year, or $69 a month
- All 57 units: 12 lessons, 34 builds, 11 depth clinics
- The VS Code and Claude Code workspace at Levels 4 and 5
- The capstone export: a finished unit becomes a folder of real files you keep
- Unlimited practice reps and retries, never metered
Level 1 Talk is open to you in full, all four lessons, graded exactly the way this one would be. Start at Meet the AI, or take the placement run and get your level first. Both are free and stay free.