I've been there, working on FreeBSD performance since 2015. I wouldn't say "many" of the early folks. From memory, I think it was more like 2. Granted, 2 of the earliest. More of the early folks were ex Level3.

That was in the openconnect team but we had a lot of ex-Yahoo throughout engineering. For example the entire observability team was ex-Yahoo when I got there in 2011.