I Asked AI to Build My Backtester… It Worked???
A complete breakdown of the Python backtesting framework I built with Claude Code — and how you can backtest any strategy from a single prompt. Covers the cash-flow engine architecture, the CLAUDE.md context file, overfitting prevention, and a live demo: MA Crossing 20/50 on SPY (2000–2026), +17.0% total return, Sharpe -0.08, 138 trades — including the full AI audit of why the result is bad and what to fix.









