Johns Hopkins Applied Physics Laboratory (APL) seeks an Ontologist to design, model, and maintain semantic knowledge representations supporting defense and aerospace missions within the Data Science & AI Department. You will develop and govern ontologies, taxonomies, and knowledge graphs that power advanced analytics, decision support, and AI/ML systems for national security and space applications. Collaborating with domain experts, you will translate complex operational concepts into machine-interpretable models, ensure semantic interoperability across systems, and contribute to standards, tooling, and best practices in knowledge engineering in a mission-driven, research-focused environment.
Responsibilities
- Design, implement, and maintain ontologies, taxonomies, and knowledge graphs for defense and aerospace missions.
- Collaborate with data scientists, AI engineers, and domain experts to capture and model complex operational concepts.
- Ensure semantic interoperability and data integration across heterogeneous systems and data sources.
- Develop standards, patterns, and governance for ontology and knowledge asset lifecycle management.
- Support AI/ML, analytics, and decision-support systems through robust semantic models and metadata.
- Evaluate and integrate ontology and graph technologies, tools, and frameworks into APL solutions.
- Document models, assumptions, and design decisions for technical and non-technical stakeholders.
- Contribute to research, prototypes, and publications in knowledge representation and reasoning.
Required Skills
- Ontology design (OWL, RDF, RDFS)
- Knowledge graph modeling (RDF, Property Graphs)
- SPARQL and graph query languages
- Semantic web standards (SKOS, SHACL)
- Data modeling and schema design
- Python or Java for knowledge engineering
- Experience with triple stores / graph databases (e.g., Neo4j, Graph
- DB, Stardog)
- Knowledge integration and data mapping
- Domain modeling for defense and aerospace
- AI/ML integration with knowledge graphs