Most backtesting frameworks are built for traders who learned to code. This is for developers who learned to trade.

Backsim is an event-driven backtesting framework that adopts PyTorch-lightning's philosophy of simple-to-use-easy-to-break abstractions, callback hooks (everywhere), and an attempt to maintain an identical backtest and production environment.

The framework supports (and perhaps even expects) models for slippage, partial fills, margin calls, etc.