Platform · 2007–now · Cloud Scale
Neo4j
Property graph database that finally made graph queries a product. Niche that pays when the graph is the domain.
Why Neo4j stuck
Neo4j stuck in fraud detection, knowledge graphs, and recommendation niches where traversals beat recursive SQL. It failed to become the default datastore because most apps are tables with extra steps. Graph hype oversold; graph fraud teams undersold.
Compare with
Related
Platform · 1974–now
SQL / Relational
Declarative data that outlived every ORM fashion cycle. Postgres and friends keep winning by being boring.
Practice · 2009–2019
NoSQL for Everything
Schema-optional databases sold as a lifestyle. Right tool for some jobs; default for none.
$ Startups ditched Postgres for document stores "because scale," then rebuilt relational integrity in application code — and paid twice when joins came back as a product requirement.
Platform · 2010–now
Elasticsearch
Full-text search and log analytics at scale. Powerful, hungry, and everywhere in observability stacks.