> but the software is so huge and poorly documented This is the case in FANG companies. The expectation is that you figure out how to effectively find the info

> but the software is so huge and poorly documented This is the case in FANG companies. The expectation is that you figure out how to effectively find the info (whether by finding the key people, reading code, etc). Since finding info takes so much time, it's also expected that you make good judgement calls on what info you research (as you cannot be proficient in the entire codebase). As for development - same thing goes. You find & form the right partnerships and have convincing enough arguments that people work with you on a project. Finding people that also benefit from your work is called "alignment" (of objectives).