Ontology Specialist

Join a dynamic healthcare data team as an Ontology Specialist supporting the design and evolution of knowledge representations that power data interoperability, analytics, and AI-driven insights. This 12-month remote opportunity is ideal for a semantic web professional who enjoys turning complex domain knowledge into structured, standards-aligned ontology solutions.
Responsibilities

• Design, build, and maintain ontologies and knowledge models using RDF, OWL, and SKOS.
• Map internal data structures and concepts to healthcare standards such as FHIR, SNOMED, and ICD.
• Query, validate, and refine knowledge graph structures using SPARQL.
• Partner with healthcare domain experts to translate tacit business knowledge into formal ontology patterns.
• Evaluate modeling approaches and communicate tradeoffs clearly to both technical and business stakeholders.
• Support knowledge graph architecture and integration with downstream AI, machine learning, and analytics environments.
• Contribute to ongoing improvements in ontology structure, data quality, and semantic consistency.

Skills

• Bachelor's degree in Computer Science, Health Informatics, Data Engineering, or a related field.
• 7+ years of experience in data or knowledge engineering, with significant focus on ontology and knowledge representation.
• Hands-on experience with RDF, OWL, SKOS, and ontology design patterns.
• Strong proficiency with SPARQL and ontology authoring tools such as Protg or similar.
• Solid understanding of healthcare data standards, including FHIR, SNOMED, and ICD.
• Experience working with graph databases such as Neo4j, TypeDB, or similar platforms.
• Strong Python skills, along with working knowledge of SQL and NoSQL systems.
• Ability to convert complex, unstructured subject matter into clear, logical models.
• Strong collaboration, communication, and problem-solving skills.

Preferred Skills

• Experience with semantic reasoners such as HermiT, Pellet, or ELK.
• Familiarity with SHACL for validation and constraint modeling.
• Exposure to terminology servers and UMLS integration.
• Interest in emerging trends in knowledge graphs, ontology engineering, and semantic technologies.
• Comfort with prototyping and testing alternative modeling approaches before finalizing designs.

Horizontal is committed to building an inclusive, respectful, and equitable workplace where different perspectives are valued and welcomed. We encourage candidates from all backgrounds to apply and bring their unique experience and ideas to the team.
By applying for this position, you acknowledge and agree that Horizontal Talent may contact you regarding your application using automated technology, including phone calls, SMS/text messages, or email, which may be delivered by our virtual AI recruiter, Alex.
Please apply through this online posting or by visiting our Job Board at Applications will be accepted for 4 weeks. For those that join the team, we offer competitive compensation and benefits including medical, dental, vision, and retirement. Check out all we have to offer and how you can become part of the Horizontal Talent Team. The pay range for this role is $51 - $90 per hour based on qualifications and experience.