Knowledge Graph & Data Engineer
I turn messy relational and lakehouse data into something you can actually query and extract insights from.
Right now I'm working on ontology and knowledge-graph adoption at a global pharmaceutical company. My portfolio spans virtual knowledge graphs, biomedical GraphRAG, and SHACL-governed semantic pipelines. Background across regulated industries: pharma, banking, and telecom.
TOP 3, ORDER BY pride desc. The rest are pinned below 👇
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Virtual Knowledge Graph Connectivity Ontop answers SPARQL over Trino against Postgres and Iceberg, staged in "rungs" and validated against a GraphDB ground truth. Why it matters: exposes relational + lakehouse data as a queryable graph without copying it (OBDA) and proves fidelity instead of assuming it.
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Biomedical GraphRAG Bench Benchmarks vector RAG against RDF GraphRAG retrievers on biomedical question sets, measuring the hop-count vs. recall tradeoff in a reproducible Docker harness. Why it matters: answers the question a pharma AI team actually asks: when does graph retrieval beat vectors? With numbers, not vibes.
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Resume Graph My résumé as an RDF knowledge graph: SHACL-validated, published as an interactive SPARQL site, and projected into tailored CV variants per application. Why it matters: a full semantic stack end-to-end, with a SHACL gate that makes unevidenced skill claims impossible to publish. (The PDF version of my CV falls out of this.)
- Languages: Python, SQL, SPARQL, Cypher
- Knowledge graphs & semantics: RDF, OWL, SHACL, ontology engineering, Neo4j, GraphDB, Ontop / OBDA, metaphactory
- Data engineering: Airflow, dbt, Docker, Terraform, DuckDB
- Warehouses & stores: BigQuery, PostgreSQL, Apache Iceberg, Trino, Redshift, Snowflake, Cassandra
- Cloud: AWS, GCP
Certifications: Neo4j Certified Professional · metaphacts (AI Metis Engineer, KG App Building, Visual Modeling for KG Engineers) · AWS Certified AI Practitioner · Claude Certified Architect – Foundations
- Deeper into knowledge-graph engineering: OBDA / virtual graphs, ontology governance, and graph-native retrieval for AI.
- Building things that put semantic data to work in regulated, real-world domains.
- Email: joseph.higaki@gmail.com
- LinkedIn: linkedin.com/in/josephhigaki

