[killface]

I've done quite a lot of work in Neo4j, and have been quite impressed with it. With my last project (which was in the 1.9.x days), we had about 2b nodes and 4b edges, with lots of properties. It was basically being used as a social graph cache (for friend-of-friend style queries).

It was remarkably simple to set up, a bit harder to tune, but we ended up getting something like 5000 req/sec at <= 10ms per query sustained for several hours.

I'd highly recommend learning neo4j, if for nothing but the paradigm shift it forces you to learn.