Posted Sep 19, 2026

Senior Ontology Engineer

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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

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

Skills & Tools

OWL, RDF/Turtle, SHACL, SPARQL, BFO, CCO, Apache Jena/Fuseki, RDF4J, Python, Git, AWS, LLMs, RAG

Job Details

About PixelRain AI

A small artificial intelligence company delivering product-lifecycle knowledge platforms and generative AI applications. — Industry: Information Technology