Directly, I am responsible for/support about 100 physical servers, approximately 500 virtual machines and somewhere in the region of 50 routers and around 100 switches. 1,000 users, $1bn revenue. Team of 7.
I'm also part of a wider global team supporting several hundred servers, over 4,000 virtual machines, hundreds of routers and switches and more besides. 10,000 users, $3bn revenue, team of 60ish.