* Serverless typically implies something accessible from more than the host you're on
* It's not zero configuration, there's at least 1 configurable parameter (albeit with a sensible default)
* I'm actually not even clear why this is a document store limited to JSON, other than you're piping it though a JSON python module.
Having done some things like this in the past, as you continue, you'll probably want to create subdirectories based on the first N characters of the UUID, but I'm not sure you wouldn't get considerably more value of just putting your json blobs into an AWS Dynamo table.