design workflows before refactor

[NickleDave]

e.g. https://github.com/keras-team/governance/blob/master/keras_api_design_guidelines.md#design-end-to-end-workflows-not-individual-functions-and-classes

write the workflows first, then refactor around those

what would a "through the Python API" workflow look like? what would "testing multiple models at once" look like?