Lead Ontologist: Semantic Web & Knowledge Graphs (TS/SCI)

InvestedintheMission; Herndon (VA); On-site; USD 137,000 - 200,000; Full time

Job summary

Vantor in the Washington, DC metropolitan area seeks an experienced Lead Ontologist to design, develop, and maintain domain ontologies and knowledge models to support Object-Based Intelligence mission requirements.

You will apply RDF, OWL, SHACL, and SPARQL, lead governance, mentor government personnel, and collaborate with analysts, data scientists, and engineers to translate mission needs into scalable knowledge frameworks.

Qualifications

• Must be a US citizen and have an active TS/SCI with CI poly.
• 12 years of experience and an advanced degree or 17 years of experience with a bachelor’s degree.
• Demonstrated experience designing and implementing ontologies, taxonomies, or knowledge graphs in operational or research environments.
• Experience applying Semantic Web technologies, including RDF, OWL, and SPARQL.
• Knowledge of ontology engineering methodologies, data modeling principles, and semantic interoperability frameworks.
• Ability to communicate complex technical concepts effectively to both technical and non-technical stakeholders.

Responsibilities

• Design, develop, and maintain domain ontologies, taxonomies, and knowledge graphs that support Object-Based Intelligence mission objectives.
• Apply Semantic Web standards and technologies, including RDF, OWL, SHACL, and SPARQL, to model, represent, and query complex data relationships.
• Establish and maintain semantic data integration frameworks that enable interoperability across internal and external object-management systems.
• Collaborate with analysts, data scientists, engineers, and Government stakeholders to capture requirements and translate mission needs into formal knowledge models.
• Develop and maintain ontology governance processes, standards, documentation, and version-control practices to ensure consistency and scalability.
• Support AI/ML initiatives by providing structured knowledge representations that enhance model explainability, interpretability, and contextual reasoning.
• Conduct ontology validation, testing, and quality assurance activities to ensure accuracy, completeness, and alignment with mission requirements.
• Provide technical leadership, mentoring, and knowledge transfer activities to Government personnel and project team members on ontology development methodologies and semantic technologies.

Skills

Ontology design

Knowledge modeling

Domain-specific ontologies

Communication with stakeholders

Leadership / mentoring

Education

Advanced degree

Bachelor’s degree

Tools

RDF

OWL

SPARQL

SHACL

Job description

Vantor in the Washington, DC metropolitan area seeks an experienced Lead Ontologist to design, develop, and maintain domain ontologies and knowledge models to support Object-Based Intelligence mission requirements.

You will apply RDF, OWL, SHACL, and SPARQL, lead governance, mentor government personnel, and collaborate with analysts, data scientists, and engineers to translate mission needs into scalable knowledge frameworks.