How this DB has 3 votes is beyond me. Now with clustering at version 3, check it out if you are interested in a document store and social graph solution that for startups specifically is an ideal entry to fast deployment. https://www.arangodb.com/download/

The combination of documents and graphs, the built-in search engine and everything connected with one query languages makes ArangoDB a unique database. Good support for cluster deployments using Kubernetes.