The drive to publish often leaves scientists working with old, inflexible, poorly documented dead end software. Even operational systems can end up being a mash of legacy systems cobbled together. As the Atmospheric Radiation Measurement (ARM) Climate Facility brings its 30+ cloud and precipitation sensitive radars into operation a concerted effort to modernize, modularize and adapt existing code and write new code to retrieve geophysical parameters from the remotely sensed signals. Due to the open nature, active development community and lack of licensing issues Python is a natural development environment choice. This presentation will outline the challenges involved in retrieving model comparable geophysical parameters from scanning weather radars, introduce the framework behind the Python ARM Radar Toolkit (Py-ART) and discuss the challenges involved in building high performance code while maintaining portability, readability and ease of use.