Really? We basically never go onsight. Ticket in with the colo and they can help.

That really works well while you have a rack or so. Afterwards, you really need people who know all the details of networking and storage. Especially if you're designing something without a SPOF.

What's changing is the scope of things that you can run on that one rack. 15 years ago, I was running clusters of 30 computers to do things that I now can do with 1.