What graph database you use and why? Any alternatives you had?

Loving Dgraph for the amazing GraphQL-like language. I believe their latest version(s) are now fully compliant.

I also used ArangoDB, back then it was a lot more stable for bulk loading than Dgraph but today I believe they're on par — Arango is multi-model which can be at times easier to reason about whilst Dgraph is a more graph-native database.

I never liked Neo4J as — back then — the horizontal scaling was impossible or extremely difficult to achieve.