Model: 3 Axes of software development ./resources/model-3-axes-of-software-development.resources/screenshot.png as opposed to functional and non-functional

  1. functional (runtime)
  2. operational (runtime)
  3. developmental (dev time)

Refactoring = keeping functional axis stable

eg. func fixed dev improves ops is kept open

(src: Video: Code as Risk • Kevlin Henney)