Lead Graph​/Ontology Engineer

Lead Knowledge Graph / Ontology Engineer (Contract)

The Opportunity

A UK-based organisation is embarking on a major data and AI transformation programme for 2026 and beyond. The focus is on unifying large volumes of semi-structured and unstructured data from diverse sources — including APIs, web data, documents, internal systems, and regulatory datasets — into a trusted, interconnected knowledge graph platform.

This programme underpins the next generation of data-driven applications, combining ontology-based reasoning, inferencing, NLP, and explainable AI to enable richer insight, discovery, and decision-making across complex legal and regulatory domains.

We are seeking a Lead Knowledge Graph / Ontology Engineer to take technical ownership of this initiative from design through to production.

Key Responsibilities

• Lead the design, build and deployment of entity-resolved knowledge graphs and ontologies, from concept to live environments
• Embed semantic and ontology-based reasoning into business-critical systems, including explainable AI and context-aware discovery solutions
• Define and maintain a standardised ontology, taxonomy and business glossary
• Design and implement ETL, streaming and CDC pipelines, including entity resolution across multiple data sources
• Clean, enrich and integrate structured and unstructured datasets into a coherent knowledge graph
• Author and optimise complex graph queries, ensuring performance, scalability and efficiency
• Develop and evaluate graph-based ML models (e.g. link prediction, anomaly detection, community detection)
• Research, benchmark and recommend knowledge graph and ontology frameworks
• Ensure compliance with relevant data protection and regulatory requirements (e.g. GDPR)
• Apply advanced NLP / NLU techniques including NER, relationship extraction, topic modelling and summarisation
• Deliver training sessions, workshops and presentations to technical and non-technical stakeholders

Required Experience

• Minimum 5+ years’ hands-on experience delivering production knowledge graph and ontology solutions
• Strong expertise with semantic web standards and tooling, including RDF, RDFS, SKOS, OWL, SHACL, SPARQL, Apache Jena, and OWL reasoners
• Experience with multiple graph databases (RDF and/or LPG), such as Graph
  
  DB, Stardog, Amazon Neptune, Neo4j, Tiger Graph or ArangoDB
• Proven background in entity resolution techniques (deterministic, probabilistic, blocking, etc.)
• Advanced Python skills with production-grade code, including experience using libraries such as Network
  
  X, Tensor Flow, PyTorch, spaCy, Hugging Face, Pandas, Num Py and Scikit-learn
• Ability to translate complex business and regulatory requirements into structured, ontology-driven models
• Solid understanding of data governance, metadata management and FAIR principles
• Excellent communication skills with the ability to explain complex concepts to non-technical audiences

Nice to Have

• Graph visualisation and UI experience (e.g. Linkurious, Ogma)
• Graph database certifications (e.g. Neo4j, Stardog)
• Experience building conversational AI solutions (e.g. RASA)

Ideally this would be a hybrid (needs must worst case) arrangement so being based close to Chester would be ideal. Fundamentally, this will be remote first,