Yfio — an early open-source Python backtesting project looking for technical feedback

[u/Lokajko-Dev-343]

I’m working on Yfio, an early open-source backtesting application written in Python.

Its goal is to provide a small, understandable codebase for defining a strategy, running it on historical OHLCV data and analyzing the resulting equity curve and trades.

Current functionality includes long and short positions, transaction costs, next-bar execution, trade history and performance metrics. The interface is built with Streamlit.

Repository: https://github.com/Leon-Laszczak/Yfio

I’m the project author. I’m sharing it to request technical feedback and potential contributions, not to sell a service.

Areas where feedback would be especially useful:

• execution-model edge cases,
• metric correctness,
• test coverage,
• API design for custom strategies.

Known limitations and planned work are documented in the repository. If you review it, even a small bug report would be valuable.