I am managing (among other things) a very large C++ library solving a very hard problem used by large scale enterprise software. The library has 9000+ tests. I

I am managing (among other things) a very large C++ library solving a very hard problem used by large scale enterprise software. The library has 9000+ tests. I haven’t had a bug in production for 5+ years. Despite making massive changes to the implementation details. I make changes and dump into production with zero worries. The productivity benefits of tests done well are amazing.