Write detailed feature specifications

Systematically create and validate machine learning features

When baseline model accuracy plateaus and feature engineering is the remaining leverage.

• · raw data
• · target variable

• · feature set
• · importance scores
• · validation curves

• · scikit-learn
• · pandas

• · Training data
• · ML baseline

• · Data leakage
• · overfitting
• · temporal misalignment

• · Leakage detection patterns
• · cross-validation protocols
• · importance rankings