I have found that the existence of a formal performance review program is a good proxy for a company's structure having grown and/or calcified to the point that

I have found that the existence of a formal performance review program is a good proxy for a company's structure having grown and/or calcified to the point that I would no longer be happy to work there. If the startup I'm currently working for someday grows to that point, I'll take it as my cue to start looking for another startup.