Algorithm Development Lifecycle (ADL) vs Walk-Forward Validation

The Algorithm Development Lifecycle (ADL) is a five-phase quality gate framework — Design, Code, Backtest, Paper Trade, Live Deploy — that every algorithmic strategy must complete before real capital is committed.

Walk-forward validation is a backtesting discipline that tests a strategy on out-of-sample historical data never used during development, verifying that its edge generalises beyond the period it was designed on.