Senior Ontology Engineer
PixelRain AI is a small, fast-moving AI company delivering an AI-powered product-lifecycle knowledge platform for a U.S. Department of War (DoW) customer: governed ingestion of technical documents, an enterprise ontology and knowledge graph, and generative-AI applications that draft maintenance-planning products and answer engineering questions with citations — running in the customer's cloud environment, with an offline variant for disconnected use. Small team, real users, working software demonstrated every sprint.
Salary: 175,000 - 228,000
Active US Security Clearance Required
What you'll do
• Design, build, and maintain the enterprise ontology (BFO/CCO-aligned) and controlled vocabularies, and map source-system data into them.
• Build and manage the knowledge graph: RDF triple store (Apache Jena/Fuseki or similar), SHACL validation, SPARQL queries.
• Build the governed ingestion path so extracted content lands in the graph with provenance and confidence, and connect the graph to retrieval and GenAI applications.
• Carry normal full-stack development work alongside the ontology work — Python services, web UI, AWS.
• Work in a small Scrum team; demo working software every sprint.
Requirements
- Active Secret OR Top Secret Clearance Required
- 5+ years of hands-on semantic-technology work: OWL, RDF/Turtle, SHACL, and SPARQL.
- Experience building ontologies aligned to an upper ontology — BFO and CCO strongly preferred.
- Production experience with a triple store (Apache Jena/Fuseki, RDF4J, or similar).
- Solid general software engineering: Python, APIs, Git — able to handle full-stack tasks (web + AWS), not ontology-only.
- Working familiarity with LLMs and RAG — you’ve connected structured knowledge to generative applications.
5+ years of semantic-technology experience with OWL, RDF/Turtle, SHACL, and SPARQL; Secret or Top Secret clearance; ontology, triple-store, Python, APIs, Git, AWS, LLM, and RAG experience.
Key Responsibilities
- designing ontologies
- building knowledge graphs
- developing applications
Skills & Tools
OWL, RDF/Turtle, SHACL, SPARQL, BFO, CCO, Apache Jena/Fuseki, RDF4J, Python, Git, AWS, LLMs, RAG
Job Details
- Category: Research and Development (R&D)
- Seniority: Senior Level
- Commitment: Full Time
- Workplace: Remote — Arlington, Virginia, United States
- Salary: USD 175,000 – 228,000 / year
- Languages: English
About PixelRain AI
A small artificial intelligence company delivering product-lifecycle knowledge platforms and generative AI applications. — Industry: Information Technology