True, but it's not quite the same as what they've done with OpenSearch/Elastic. Also, from what I've read, despite claims, the compatibility isn't complete, esp with stuff like aggregations.

There are a few use-cases where you'd want the ability to have a managed/hosted vanilla Mongo setup vs an emulated experience.

Kinda blocked on the compatibility front after the 4.0 API though, eh?

Not if the recent Oracle vs Google supreme court ruling is to be acknowledged.

DocumentDB is to MongoDB 4.0+ as Dalvik runtime was to JVM.

Here is their 4.0 compatibility update: https://docs.aws.amazon.com/documentdb/latest/developerguide...

Time will tell...MongoDB 4.2 APIs are under SSPL

"Amazon DocumentDB implements the Apache 2.0 open source MongoDB 3.6 and 4.0 APIs by emulating the responses that a MongoDB client expects from a MongoDB server, allowing you to use your existing MongoDB drivers and tools with Amazon DocumentDB."

https://aws.amazon.com/documentdb/

IANAL