Code? I know people that have caused big projects to fail by just showing up at the meetings. The amount of damage a -10x idiot can do to a project is just mind boggling.
Here is my unsolicited advice to young players: if you end up in a project with a -1x (or worse) guy who is also the darling of the PM or CEO: no matter how hard you work you cannot save this project, don't wait for the shit to hit the fan, give them your two week notice today!