Senior Ontology Engineer

SELECT* is a professional team of recruiting specialists who are searching for talents in Ukraine, Europe, and the USA. Currently, we are looking for a Senior Ontology Engineer for XTEL.

Join XTEL as a Senior Ontology Engineer to lead the development of our knowledge representation layer. Define and manage ontologies and semantic rules to support AI-driven systems, enabling advanced search, interaction, and integration with LLM-powered agents. Collaborate with cross-functional teams to expose and utilize the knowledge graph effectively. Take ownership of the ontology strategy, guide technical execution, and drive innovation at the intersection of semantics and AI.

Key Responsibilities

• Define, model, and manage complex ontologies and semantic rules that underpin intelligent system behavior.
• Design and implement the semantic layer enabling search, interaction, and orchestration for LLM-based AI agents.
• Lead the development and exposure of the knowledge graph, integrating ontologies with relevant tools and services.
• Collaborate closely with AI Engineers and Product teams to translate business needs into semantic structures.
• Guide the strategic direction of ontology development, ensuring scalability, reusability, and alignment with technical architecture.
• Mentor junior team members and promote best practices in ontology engineering and semantic modeling.
• Stay informed about the latest advancements in semantic web technologies, knowledge representation, and AI integration.

Qualifications

• A Bachelor’s degree in Computer Science, Information Science, or a related field.
• At least 7 years of experience in ontology engineering, knowledge representation, or semantic technologies.
• Proven experience defining ontologies and semantic rules (e.g., OWL, RDF, SHACL).
• Hands-on experience with tools and frameworks for building and exposing knowledge graphs (e.g., GraphDB, Protégé, SPARQL endpoints, Stardog, Ontotext).
• Deep understanding of the role of ontologies in enabling search, reasoning, and interaction for AI systems.
• Ability to lead complex projects, from concept to implementation, in cross-functional environments.
• Advanced proficiency in English, with excellent written and verbal communication skills.

Nice to have

• Experience working with or integrating LLMs and AI agents.