Senior Ontology Engineer

InterImage; Arlington (TX); On-site; USD 175,000 - 228,000; Full time

Job summary

PixelRain AI, a fast-moving AI company, seeks a specialist to design and maintain an enterprise ontology and governed knowledge graph. You will map source data into ontologies aligned to upper ontologies and build RDF graphs with SPARQL, SHACL validation, and production-grade triple stores.

You’ll also perform full-stack work in Python, APIs, and AWS, in a small Scrum team delivering demonstrable software each sprint. A security clearance is required.

Qualifications

• 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).

Responsibilities

• Design, build, and maintain the enterprise ontology and mapped source data.
• Build and manage the knowledge graph with RDF stores and SHACL validation.
• Connect the graph to retrieval and GenAI applications with provenance and confidence.
• Carry full-stack work (Python services, web UI, AWS).
• Work in a small Scrum team; demo working software every sprint.

Skills

Semantic technology

OWL

RDF/Turtle

SHACL

SPARQL

Python

APIs

Git

Knowledge graph

RAG

Tools

Apache Jena/Fuseki

RDF4J

Job description

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.

• 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.