Compare backtest results before and after migration. Even with similar Python roots, differences in data handling and fill assumptions between Lean and Zipline can shift results.
Migrating to Ziplime
From QuantConnect & Lean
Bringing Lean strategies to Ziplime
If you have strategies built on QuantConnect, running on the open-source Lean engine, Ziplime’s AI can help port that logic to its own Python/Zipline-based engine.
Because both Lean and Ziplime use Python, migration is often more direct than from a non-Python platform — but the underlying APIs differ (data access, order placement, scheduling), so the agent team will still rewrite strategy internals against Ziplime’s API rather than doing a literal copy-paste.