Today we know very well how to start a new project on a greenfield and how to build a good architecture. But most of us work in projects that have been around for a long time and whose architecture (to put it mildly) is not quite so beautiful. “Monolith” and “Big Ball of Mud” are the unflattering labels put on such systems. This talk will show how we can introduce (or bring back) structure. Every system is different here, so it’s important to first understand where you are. Then the right steps have to be taken. I present a catalog of refactorings to choose from and heuristics which are the right choices. The catalog contains refactorings that help to cure: BBOM architecture, anemic domain models, and badly organized teams.