Bob van Luijt
Co-Founder & CEO, Weaviate | Creator of Open-Source AI Vector Database | Agentic RAG Architect
Co-founder and CEO of Weaviate, the industry-leading open-source AI vector database and knowledge infrastructure platform. Architected scalable vector indexing (HNSW, flat, dynamic quantization), multi-modal search, and native hybrid retrieval integrating BM25 with dense semantic vectors. Pioneered generative search modules enabling real-time LLM grounding and agentic memory retrieval for thousands of organizations worldwide.
Areas of focus
Professional niches
Proof of Work
Hybrid Search: Merging Sparse and Dense Retrieval for Generative Grounding
Authored the technical blueprint explaining Relative Score Fusion (RSF) and reciprocal rank fusion algorithms for combining sparse lexical matching with dense vector embeddings to maximize RAG precision.
Weighting hyperparameter tuning between keyword and vector dense scores varies by industry domain and query semantics.
Context: BM25 scoring, dense vector similarity, reciprocal rank fusion.
View missionWeaviate: Open-Source AI Vector Search Engine
Engineered a low-latency, cloud-native vector database written in Go featuring custom HNSW implementations, product quantization (PQ), and native GraphQL/REST/gRPC interfaces.
High-dimensional HNSW vector graphs require substantial resident memory footprints without product quantization.
Context: Go, vector math SIMD intrinsics, distributed Raft clustering.
View mission