Neo4j
What it is: Leading graph database. Native graph storage and processing. Relationships are first-class citizens, not foreign keys.
What It Does Best
Relationship queries. "Friends of friends," network analysis, recommendation engines. What's painful in SQL is natural in Cypher.
Pattern matching. Find complex patterns across connected data. Fraud detection, knowledge graphs, social networks.
Real-time traversals. Multi-hop queries stay fast. No join explosions at query time.
Pricing
Community Edition: Free, limited to single instance. Enterprise: contact sales. Neo4j Aura (cloud): $65/mo starter.
When to Use It
✅ Social networks and connections
✅ Recommendation engines
✅ Fraud detection and network analysis
✅ Knowledge graphs and master data
When NOT to Use It
❌ Simple tabular data (use relational DB)
❌ Aggregate analytics on large datasets (use data warehouse)
❌ Unconnected data with few relationships
Bottom line: If your data is about connections and relationships, stop fighting SQL joins. Neo4j makes complex relationship queries simple and fast. Cypher is intuitive once you think in graphs.