In my case, I turned a career in driver and low-level algorithm coding into a career in AI in <2 years emphasizing the ability to implement AI algorithms in C/C++ and CUDA. That said, when Tensorflow Monkeys can make $300K right out of school, imagine how someone who could bang the metal directly could do...
TLDR: Chance favored the prepared skill set. No fancy degree required, just results.
PS Before that, I blew a boring blind-allocated gig at Google insisting that GPUs were about to play a huge role there a year before they acquired DNNResearch. I even tried to join the very beginnings of the Google Brain team but they didn't have any openings or the budget/willingness to make one for me.