Welcome @ajwerner !
Databases make a great place to persist data of course. Akka inverts that database world, such that the in-memory Akka system is the source of truth and the db is used to persist, and recover entities as needed. I think that @james did an outstanding job capturing this in a post on Hacker News (specific to Akka Serverless but applicable to the broader Akka story, I think): The best of serverless and state without any of the hassle | Hacker News.
Historically, Akka customers have leveraged Cassandra. We have spent much time investing in non-Cassandra based integrations though (JDBC (Custom, Amazon RDS, GCP Cloud SQL) :: Akka Platform Guide) since we have seen other DB technologies become quite useful to the Akka user ecosystem.
There are many other DB options available to developers these days and we intend to provide flexibility of choice, i.e. you can pick which DB works best for you respective of cost, performance and data storage requirements. Yugabyte, CockroachDB, Couchbase, Fauna, DynamoDB, etc. are all great options and in some cases have different optimized values that might be critical for your applications.
I’d be happy to continue the discussion if the above is interesting but not complete enough for you!
Thanks for the question!