For years, "code review" in iOS meant "email your patch set to a particular email address, which would format your patch and send it to a mailing list". That list would be populated with people who could approve or disapprove it.

The server that ran that conversion was a MacBook sitting in a pretty random "server" room that included MacBooks, iMacs facing a wall, and other Mac devices used as headless servers.

Useful more than a decade ago, still useful now!