One company I worked at in a major US city allowed individual teams to perform their own hiring. The division I was in had employees mostly from outside the US,

One company I worked at in a major US city allowed individual teams to perform their own hiring. The division I was in had employees mostly from outside the US, and the autonomy given to each team led them to form their own to ethnic enclaves. There was a team of Indians, Chinese, Koreans, etc. When I first started, I couldn't believe it. That doesn't happen merely by change, at least not that pervasively and consistently. It sounds like this is occurring everywhere.