Mary Poppendieck started her career as a process control programmer, moved on to manage the IT department of a manufacturing plant, and then ended up in product development.

Mary considered retirement 1998, but instead found herself managing a government software project where she first encountered the word waterfall. When Mary compared her experience in successful software and product development to the prevailing opinions about how to manage software projects, she decided the time had come for a new paradigm. She wrote the award-winning book Lean Software Development: An Agile Toolkit in 2003 to explain how the lean principles from manufacturing offer a better approach to software development.