Now I understand your point of view: several teams working on the same infrastructure, each one uses the framework that best suits them. It is following the DDD of having different independent domains and isolated aggregates that communicates and collaborates. Here it is no doubt that the best way is to follow BDD for the testing and mock when it is necessary, like any other DDD environment. It is not solely a frontend matter, but a full-stack one. My experience in that field is that RTL works well with the minimal required mocks —specially with not everyone is React (comparing to Enzyme)—, but probably your experience is different. I welcome you to contribute with some examples and practices that you have found. I would enjoy reading the links. Thanks!