Feature Engineer Optimization in HyperparameterHunter 3.0

Lots of people have different definitions for feature engineering and preprocessing, so how does HyperparameterHunter define it? We're working with a very broad definition for "feature engineering", hence the blurred line between itself and "preprocessing". We consider "feature engineering" to be any modifications applied to data before model fitting -- whether performed once on Experiment start, or repeated for every fold in cross-validation. Technically, though, HyperparameterHunter lets you define the particulars of "feature engineering" for yourself, which we'll see soon. Here are a few things that fall under our umbrella of "feature engineering": A fair question since Feature Engineering is rarely a topic in hyperparameter optimization.