What makes me an awful team member
If I ever see code that I think could be written in ‘much better’ way, I have a really big temptation to rewrite/refactor it. Sometimes this can be good, eg. when I spot buggy code. Sometimes it depends, as I often spot the code that is (or I think is) ‘sub-obtimal’.
The worst situation is when the code is buggy, but some other part of the codebase depends on that code being buggy. If you find one, and not the other, it’s bad.
Working on some big unknown codebase remotely (I’m a contractor for one game in development) makes this worse. I must resist the temptation to alter the code, no matter how bad it looks…