Then you change from MySQL to postgres and you have to tell everybody to start another container. Then you have 5 projects, are they all using the same password

Then you change from MySQL to postgres and you have to tell everybody to start another container. Then you have 5 projects, are they all using the same password? Here we're talking about record/replay mocks, which are based on a real database. So, of course somebody will have to run that container with MySQL so that the tests will be run in record mode (e.g. when developing the tests). But, then if your teammates don't develop those tests, they don't technically need a real database. You still want them to run your tests because those tests might depend on some course your teammates touch (e.g. some common library code)