> At Amazon, practically every service is built on top of AWS - a proper vote of confidence!

Not only this, but practically most, if not all, of the AWS services use DynamoDB, including use cases that are usually not for databases, such as multi-tenant job queues (just search "Database as a Queue" to get the sentiment). In fact, it is really really hard to use any relational DB in AWS. I mean, a team would have to go through a CEO approval to get exceptions, which says a lot about the robustness of DDB.