And a nontrivial number of current university faculty.
(Fei-Fei Li recently left, as a notable example, and I can name 3-4 profs from my alma mater who are also employed at Google in various capacities)
Indeed, and even stranger arrangements. I know one professor who comes to work for us every summer (with hilarious HR boundary condition consequences every year).
And I’m sure this is true of any large university with a competitive computer science program.