Ontology & Knowledge Graph Data Engineer (Hybrid + Equity)

Valarian; Greater London; Hybrid; GBP 90,000 - 130,000; Full time

Benefits offered by this job

Equity

Competitive salary

Employer pension

Private health insurance

Hybrid work

Gym memberships

Company retreats

Job summary

Valarian is seeking a senior data engineer to build and scale ingestion pipelines, ontologies and graph-based knowledge graphs for secure, frontier-class AI tools. You will collaborate with product teams and domain experts.

This role focuses on production-grade Python, SQL/NoSQL, and data provenance, with graph databases (Neo4j/RDF) and robust data models. London-based, hybrid office presence is encouraged.

Qualifications

• Proficiency in Python for building ingestion pipelines.
• Strong SQL skills with indexing and migrations.
• Experience with NoSQL databases and consistency trade-offs.
• Production experience with graph databases (Neo4j/Cypher or RDF/SPARQL).
• Ontology design with stable identifiers and versioning.
• Understanding property graphs vs RDF knowledge graphs.
• Experience integrating heterogeneous data sources with provenance.
• Ability to model domain requirements into reliable data interfaces.

Responsibilities

• Define and evolve ontologies covering entities, relationships, and business rules.
• Build ingestion and transformation pipelines from various sources (APIs, databases, documents).
• Implement entity resolution, deduplication, provenance, and source reconciliation.
• Design and maintain graph and relational schemas and NoSQL structures.
• Develop efficient queries and data interfaces for applications, retrieval services and AI tools.
• Implement automated tests for transformation correctness and data integrity.
• Preserve source permissions, classification and retention in derived datasets.
• Own model evolution and migration logic with DataOps on deployment and recovery.

Skills

Python engineering

SQL

NoSQL

Graph DB

Ontology design

Knowledge graphs

Data integration

Data evolution

Requirements analysis

Job description

Valarian is seeking a senior data engineer to build and scale ingestion pipelines, ontologies and graph-based knowledge graphs for secure, frontier-class AI tools. You will collaborate with product teams and domain experts.

This role focuses on production-grade Python, SQL/NoSQL, and data provenance, with graph databases (Neo4j/RDF) and robust data models. London-based, hybrid office presence is encouraged.