LEAD DATA SCIENTIST
Security Knowledge Graphs & Cyber AI
Role Level
Lead
Experience
10+ years overall; 5+ years in AI/ML or graph analytics
Location
Flexible / Hybrid
Employment Type
Full-time
Role Purpose
Lead the design, engineering, and operationalization of enterprise Security Knowledge Graphs that connect security telemetry, assets, identities, vulnerabilities, threats, controls, and incidents into a trusted intelligence layer. The role is highly hands-on and combines data science, graph engineering, cybersecurity analytics, semantic modeling, and technical leadership to enable attack-path analysis, threat investigation, exposure prioritization, GraphRAG, and AI-assisted security operations.
Key Responsibilities
• Design the Security Knowledge Graph architecture, ontology, taxonomy, entity model, relationship model, provenance model, and lifecycle standards.
• Build production-grade graph ingestion and transformation pipelines for SIEM, EDR/XDR, IAM/PAM, CMDB, vulnerability scanners, cloud security platforms, threat intelligence feeds, security data lakes, and case-management systems.
• Develop entity extraction, identity resolution, deduplication, schema mapping, relationship inference, confidence scoring, temporal modeling, and graph enrichment capabilities.
• Model assets, applications, users, service accounts, privileges, vulnerabilities, misconfigurations, controls, alerts, incidents, indicators, threat actors, campaigns, tactics, techniques, and procedures.
• Implement graph analytics for attack paths, blast radius, privilege escalation, lateral movement, toxic combinations, identity exposure, control gaps, and vulnerability prioritization.
• Build and evaluate graph algorithms and ML models including centrality, community detection, similarity, anomaly detection, node classification, link prediction, embeddings, and Graph Neural Networks.
• Design GraphRAG and knowledge-grounded security assistants that combine graph traversal, vector retrieval, structured evidence, LLM reasoning, citations, and human approval controls.
• Partner with SOC, threat intelligence, IAM, vulnerability management, cloud security, architecture, data engineering, and product teams to convert operational problems into reusable graph-powered capabilities.
• Own technical design reviews, coding standards, model validation, observability, performance tuning, security controls, documentation, and production-readiness gates.
• Mentor data scientists and engineers while remaining accountable for prototypes, reference implementations, critical code, troubleshooting, and complex customer or stakeholder demonstrations.
Mandatory Hands-on Technical Skills
• Knowledge graphs: Ontology and semantic model design; property graphs and RDF; graph schema evolution; knowledge representation; provenance; graph quality; entity and relationship resolution.
• Graph platforms: Deep implementation experience with Neo4j and Cypher; working knowledge of at least one additional platform such as Amazon Neptune, TigerGraph, Azure Cosmos DB Gremlin, ArangoDB, or JanusGraph.
• Graph data science: Neo4j Graph Data Science, NetworkX, PyTorch Geometric or DGL; graph embeddings, pathfinding, similarity, clustering, link prediction, node classification, anomaly detection, and GNN development.
• Programming and engineering: Advanced Python and SQL; APIs; test automation; data structures; distributed processing; Git; CI/CD; containers; infrastructure awareness; production debugging and performance optimization.
• Data engineering: Spark or Databricks, Kafka or equivalent streaming, ETL/ELT, batch and real-time pipelines, data contracts, lineage, cataloguing, quality rules, and scalable cloud storage.
• Cybersecurity: SOC workflows, threat hunting, incident response, detection engineering, vulnerability and exposure management, IAM/PAM, Zero Trust, cloud security, and security control mapping.
• Security standards: Practical use of MITRE ATT&CK, STIX/TAXII, CVE, CWE, CAPEC, NIST frameworks, CIS Controls, and common threat-intelligence vocabularies.
• GenAI and GraphRAG: LLM-based extraction, retrieval orchestration, agent/tool integration, prompt design, evaluation, grounding, guardrails, explainability, and evidence traceability.
• MLOps and observability: Experiment tracking, model versioning, deployment, monitoring, drift and quality checks, auditability, access controls, secrets management, and cost/performance management.
Security Knowledge Graph Engineering Expectations
• Create canonical entity and relationship definitions with stable identifiers, temporal context, source lineage, evidence attributes, confidence scores, and access-control classifications.
• Develop reusable connectors and parsers for structured, semi-structured, and unstructured security sour
Skills Required
- 10+ years of overall professional experience
- 5+ years of experience in AI/ML or graph analytics
- Hands-on ontology, semantic model, property graph, RDF, knowledge representation, provenance, and entity or relationship resolution experience
- Deep implementation experience with Neo4j and Cypher
- Working knowledge of at least one additional graph platform, such as Amazon Neptune, TigerGraph, Azure Cosmos DB Gremlin, ArangoDB, or JanusGraph
- Experience with Neo4j Graph Data Science, NetworkX, PyTorch Geometric, or DGL
- Experience developing graph algorithms, embeddings, pathfinding, similarity, clustering, link prediction, node classification, anomaly detection, and graph neural networks
- Advanced Python and SQL skills
- Experience with APIs, test automation, data structures, distributed processing, Git, CI/CD, containers, production debugging, and performance optimization
- Experience with Spark or Databricks, Kafka or equivalent streaming, ETL/ELT, data contracts, lineage, cataloging, quality rules, and scalable cloud storage
- Knowledge of SOC workflows, threat hunting, incident response, detection engineering, vulnerability and exposure management, IAM/PAM, Zero Trust, cloud security, and security control mapping
- Practical experience with MITRE ATT&CK, STIX/TAXII, CVE, CWE, CAPEC, NIST frameworks, and CIS Controls
- Experience building or evaluating LLM-based extraction, retrieval orchestration, GraphRAG, agent/tool integrations, prompt designs, grounding, guardrails, explainability, and evidence traceability
- Experience with MLOps, experiment tracking, model versioning, deployment, monitoring, drift and quality checks, auditability, access controls, secrets management, and cost or performance management
- Technical leadership, design reviews, coding standards, model validation, documentation, production-readiness reviews, and mentoring experience
What We Do
Test Triangle is a Dublin-headquartered technology services company founded in 2012. It helps organizations transform operations through IT service management, digital transformation, software testing and quality assurance, cloud solutions, consulting, managed services, and recruitment. The company also provides application testing, DevOps, robotic process automation, software and mobile development, technology training, staffing, and resource augmentation across Ireland, the UK, and international markets.






