I met a seasoned game dev who complained to me he was only ever hired at the end of projects to speed up the code a bunch of mid/junior level game devs the company had used to actually make the game. Basically he said there was only so much time he'd get given, and he'd have to go for low hanging fruit and might miss stuff.

We've only got a couple of game dev shops in my city, so not sure how common that is.