I was hoping for more advice for those pursuing this transition, but it was more just an account of Google's incredible support for his wish to change careers. He never mentions his employer by name, but I think it'd be helpful to point this out. Those of us on the outside (I and a few other DS's I know are doing this) are spending 6 months or more grinding leetcode and studying system design, doing mock interviews, and applying to hundreds of jobs. So it can be much more painful if you don't have an employer that holds your hand (and pays you) through this entire transition.