I've written 35k LoC with this tool, and it does require some taste but not intractably so. A couple of rules of thumb: - Don't use layers in too fine-grained

I've written 35k LoC with this tool, and it does require some taste but not intractably so. A couple of rules of thumb: - Don't use layers in too fine-grained a manner. Often if I need to change two lines in a function but they're separated by 6 lines I err on the side of replacing the entire paragraph or even the entire function. Each layer should be readable in a self-contained manner as much as possible. - I never invalidate tests in an earlier layer. You never want to be in a situation where a layer lies to you about what desired behavior is.