Downloads are powered by Go, which was a huge port from C++.
I'm pretty sure there is quite more stuff now, but those known are not much to write home about. Even downloads is not some "huge port" -- the presentation mentions "14,032" lines.
It was Vitesse:
The parent comment was asking about projects so I presented one that sprung to mind.
> Even downloads is not some "huge port" -- the presentation mentions "14,032" lines.
Yes, it mentions "39 files (14,032 lines) deleted" which is not small in my mind. Not to mention they heavily leveraged the standard library and some other projects like groupcache.