Water flowing uphill
Requirements first, then top-down, is the way I learned it. It's a little quaint next to agile. Not sure what to make of this latest one though.... "Celonis works by recording a users' application logs, and by applying machine learning to data across a number of applications, purports to figure out how processes work in real life." Translation: We wrote this program, but we have no idea what it does. And we don't want to tip off the users by asking them, so let's spy on them instead.