Guess my career has gone such that I've always looked to code and git history to wrap my head around, because the documentation people write is unreliable.
Particularly in enterprise, where for some reason there's some "developer" who writes a word document and then buggers off while someone else actually does the coding and the relationship between actual code and document drift because the "architect" never had to reconcile his document with the realities.
It's kind of weird because it kind of acts like 80/20, but you end up doing a significant effort to unwind things back to 60/40 to start trying to massage it to what you really need.
Assuming it's one of the areas where it does relatively strongly, other areas it will flounder far worse and for some scenarios it can essentially one shot a working thing, if it is really a supremely common and simple thing.