This quote from John Carmack speaks very succinctly to the problems that many abstractions in a code base can cause, and it's a constant reminder for me when building out business logic.
> "A large fraction of the flaws in software development are due to programmers not fully understanding all the possible states their code may execute in."
https://www.gamasutra.com/view/news/169296/Indepth_Functiona...