Across multiple servers or do you still have to provision your server to handle peak load?

Yes, you can do that the same way Amazon does it. Like I said, Amazon packaged existing tech in an easy to use way.

That still begs the question, why am I as a developer wasting time fiddling with infrastructure that I could just throw a little money and a yaml file at AWS and let them do it? How am I adding a business value that will make my company money doing grunt work?

I was explaining why I consider it to be "managed cgi-bin".