Was Amazon actually the first customer for AWS (being a very early customer counts). I've heard that they were, but I've also heard that the AWS guys designed for a different customer base first.

Like the eBay Pez story it makes sense and ads credibility for the narrative to be that Amazon was the first customer for AWS. But it feels like a very unamazon thing to do, given that so much of its customer base isn't running the kind of enterprise jobs that an Amazon scale company needs.

(Either way I imagine almost all of Amazon does run on AWS these days and I'm sure the transition took a long time)