On a good team of engineers, I think a consensus generally builds when someone is not performing at the necessary level. Either you are constantly fixing their code, or they are slowing down the team because they cannot produce fast enough. Eventually this will bubble up to the manager, and they can then decide to shuffle them around, mentor them, put them on an improvement plan, or let them go.
Perhaps, if you work on a team of peers. I'm not speaking from personal experience in terms of managerial problems, but I have often been the only person doing my sort of work, which makes peer review challenging.
And I don't think that Netflix shuffles, mentors or warns people -- I think they just bounce you out of the company. It's been put to me as "they pay top of market, so they shouldn't have to deal with any personnel issues."
