At Microsoft itself. If a manager has $100 budget for hikes and rewards, she has to invisibly stack rank to distribute it with some logic (and not give $10 to each in 10 people team)[0].

Stack ranking was not about firing at Microsoft (or any other place), it was about distribution of bonus and hikes.

[0]Spreading the peanut butter: https://www.compensationcafe.com/2014/03/spreading-the-peanu...