I'm not sure it's the biggest deal in the world, plus real-world market presence data is regularly detailed in shareholder reports for various companies.
You could take low-end instance specifications and standard industry stacks and extrapolate forward how many instances they might need to maintain at a maximum, but those numbers are going to be off.
Are they running 400 low-end front-end instances across the globe? Probably, (plus the 40 or so other services they claim to need, multiplied by region count at a minimum) and that would actually be well below realistic and reasonable for a company like Amazon. You can take a bunch of regional instances that handle roughly 200 req/s and make that work.
You could take low-end instance specifications and standard industry stacks and extrapolate forward how many instances they might need to maintain at a maximum, but those numbers are going to be off.
Are they running 400 low-end front-end instances across the globe? Probably, (plus the 40 or so other services they claim to need, multiplied by region count at a minimum) and that would actually be well below realistic and reasonable for a company like Amazon. You can take a bunch of regional instances that handle roughly 200 req/s and make that work.