There is Khepri, Riak and OpenRiak, the Couch family of DB tech, Hypermnesia (not much beyond poc stage), and probably I am missing a few. I think the BEAM is one of the ecosystems with most databases, tbf, what are you missing? I have used Mnesia in prod and yes, it’s a pain, you need to build a lot of boilerplate around it to keep it from corrupting your data for one reason or another, but Riak for example is fairly battle tested and works kind of out-of-the-box.
