Senior Ontology Engineer

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

Job summary

PixelRain AI is a fast-moving AI company delivering an enterprise knowledge platform for a U.S. DoW customer. The role focuses on designing and maintaining an ontology and knowledge graph, integrating standard semantic technologies with scalable Python services and AWS deployments.

You will work in a small Scrum team within a secured environment, delivering governance-anchored content pipelines and supporting GenAI applications with proven provenance.

Qualifications

• 5+ years of hands-on semantic-technology work: OWL, RDF/Turtle, SHACL, and SPARQL.
• Experience building ontologies aligned to an upper ontology — BFO/CCO preferred.
• Production experience with a triple store (Jena/Fuseki, RDF4J, or similar).

Responsibilities

• Design, build, and maintain the enterprise ontology and map source data into them.
• Build and manage the knowledge graph: RDF store, SHACL validation, SPARQL queries.
• Create the governed ingestion path so content lands in the graph with provenance and confidence; connect to retrieval and GenAI apps.
• Carry full-stack development work (Python services, web UI, AWS).
• Work in a small Scrum team; demo working software every sprint.

Skills

Semantic tech

OWL

RDF/Turtle

SHACL

SPARQL

Python

APIs

Git

LLMs

RAG

Tools

Apache Jena

Fuseki

RDF4J

AWS

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

What You'll Do

Active US Security Clearance Required

• 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