create categorical encodings only once, possibly in polars.
create numpy arrays only once or try at least to do it memoryless in polars with a single filter one the validation
consider trade off between computation and memory by precaching features before modal deployment
create categorical encodings only once, possibly in polars. create numpy arrays only once or try at least to do it memoryless in polars with a single filter one the validation consider trade off between computation and memory by precaching features before modal deployment