Ontology Engineer

Location: Poland, Portugal, or The Netherlands

Salary: EUR 3,000–4,950 gross per month; final compensation depends on experience, location, and professional growth.

Company

hirify.global is a global technology provider delivering data analytics and AI-powered solutions for organizations across multiple industries.

What you will do

• Implement and extend RDF, RDFS, and OWL ontology schemas in a graph database.
• Build and maintain SHACL validation shapes, identify data-quality issues, and support schema consistency checks.
• Write SPARQL queries and graph traversals for data science and product use cases.
• Develop PySpark and Databricks pipelines that transform TV viewership and web activity events into graph attributes.
• Implement derivation logic, validate outputs before graph loading, and support incremental refresh processes.
• Collaborate with senior ontology, data engineering, product, operations, and data science stakeholders on graph design and pipeline development.

Requirements

• 2+ years of experience in knowledge graph development, semantic data modeling, ontology engineering, or a related field.
• Practical knowledge of RDF, RDFS, OWL, and SPARQL, with experience using a triplestore or graph database.
• Familiarity with SHACL or equivalent graph-data validation frameworks.
• Strong Python skills, including testing, documentation, and production-quality code.
• Understanding of data modeling, taxonomies, hierarchies, entity resolution, and data matching.
• Bachelor’s degree in Computer Science, Information Science, Mathematics, or a related field; English at Intermediate+ level or above.

Nice to have

• Experience with Amazon Neptune, Stardog, or another RDF-native triplestore.
• Knowledge of PySpark and Databricks for large-scale event processing.
• Experience with embedding models, vector search, semantic similarity, LLM APIs, or RAG for entity matching and ontology enrichment.
• Background in media, entertainment, ad tech, identity resolution, probabilistic record linkage, or device graphs.

Culture & Benefits

• Projects with organizations in FinTech, Healthcare, Retail, Telecom, and other industries.
• Mentoring, onboarding support, professional development, and career growth opportunities.
• Corporate training portal and compensation for professional certifications such as AWS and PMP.
• Private health insurance and sports compensation depending on the employment type.
• Additional annual-bonus opportunity of up to EUR 1,000 per month based on expertise and participation in company activities.