I’ve seen the inside of the Google and Amazon tech stacks. There are common threads that run through them and also, I bet, through
most BigTechCos. Here and there down the stack is a lot of C++ and vestigial remnants from earlier days, Perl or PHP or whatever.
Out in front of humans, of course, JS. But in between, there are oceans and oceans of Java; to a remarkable degree, it runs
the Internet. Except for, here and there, you find a small but steadily increasing proportion of Go.