That's not a comment on the technical benefits. It's a comment on turning around battleships.

Porting large projects is lots of work, especially when there's plenty of stuff to do that directly impacts the customer. New projects are a different story.

Well, given that YouTube is one of Google's most resource-intensive sites (remember that acquisition back in 2006?), I'd say that alone makes them a pretty heavy user; plus, that's just the bit they've open-sourced. The Go team makes constant reference to assorted internal infrastructure projects for which Google uses Go, but which have not been and which probably never will be publicized.

youtube is part of google, and apparently all mysql requests at youtube now go through vitess (or so I read). That strikes me as pretty heavy use.

I recall reading somewhere that Go was used for some other internal projects, but never heard what exactly for. So maybe it was just someone talking about some greenfield "20% time" projects or something.

This is flat out wrong.

what? could you elaborate?

And... where and how did you draw such a conclusion?