> What happens if you don't go far enough up, abstraction wise? Or you end up with a flat hierarchy of isolated modules that can do one thing and one thing onl

> What happens if you don't go far enough up, abstraction wise? Or you end up with a flat hierarchy of isolated modules that can do one thing and one thing only but can do it well. Architectures are what can't be changed easily and it is easier to change what is small. Architectures that try hard to accommodate every case always end up getting in the way of everything.