For exploring relationships in connected data and for boosting ML model performance, Neo4j is a powerful graph data platform. It's got data science and machine learning support, vector search and real-time analytics. With graph-native performance, flexibility and enterprise-level security, Neo4j is well suited to large-scale data sets.
Another top contender is Vespa, an online service that marries AI with big data. It's got a unified search engine and vector database, and supports fast vector search and filtering with machine-learned models. Vespa is good for search, recommendation and personalization, so it's a good choice for ML model performance improvements.
Last, Qdrant is an open-source vector database and search engine that's fast at processing high-dimensional vectors. It's got cloud-native scalability and supports a variety of use cases like advanced search and recommendation systems. Qdrant is available on several cloud markets and offers flexible pricing, so it's a good option for data science work.