Job Specifications
Lead Knowledge Graph / Ontology Engineer (Contract)
UK (Hybrid)
⏳ Initial 6-month contract (extensions likely)
£600–£700 per day (outside IR35, experience dependent)
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 GraphDB, Stardog, Amazon Neptune, Neo4j, TigerGraph 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 NetworkX, TensorFlow, PyTorch, spaCy, Hugging Face, Pandas, NumPy 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)
Additional programming languages (Java, JavaScript, C++, etc.)
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,