The most surprising thing about this is that test and staging are 1:1 duplicates of production. At the companies I've worked at dealing in scale, that has never been the case.

"Oh, you run 10 servers and 2 load balancers across these 2 sub-systems? Here's 2 servers and a toy whistle for staging."

But then again, I suppose that's what you get when you can dump hundreds of millions of dollars on a problem over a couple years.