Code without use case tests that are solid, fast, and cover all use cases. I am happy to work with any code written in any style as long as the tests are solid. Tests done well are basically a machine checkable specification of what the software is supposed to do. It allows you to jump in and make large changes without breaking anything. I am maintaining a very large system written in C++ and I routinely refactor and make system wide changes without fear. I haven’t had a bug in production for 5+ years. Imagine how productive you will be when you never have to spend time fixing urgent production bugs.