The Single Responsibility Principle and the Dry Principle

The litmus test for me is something like this. If my boss comes to me and he says, well, we need to change this business logic, right? And I, with the knowledge of the code, look at the code and say, okay, but if we change that, then we're also going to have to change this. His reaction tells me whether or not I've followed the single responsibility principle correctly. We should have maybe think, as I was reading this actually, of the thing you've mentioned before, the one second's worth of microservices,. Like it's really hard to measure how big something is. You have to kind of come up with some heuristic,