Fender showcased how much they use AWS at the recent re:Invent. They moved more services to AWS, while still increasing usage, and still reduced their AWS spend. Because it sounds like they did it the right way and used AWS services effectively.

I've spent a lot of time helping web developers, that don't have a ton of infrastructure experience, that get into AWS and they almost always do it the wrong way (the most expensive way). As in, they take whatever they were running on-premise and just throw it on EC2.