Senior AI & Systems Architect — GenAI Decisioning & Governance

HMRC; United Kingdom; On-site; GBP 120,000 - 180,000; Full time

Job summary

HMRC seeks a Senior AI & Systems Architect to lead the architecture and engineering of an AI-assisted decision-systems prototype. You will design the agentic workflow, evaluation framework and control boundaries that connect authoritative source material to controlled representations, a deterministic language, standard data, and downstream implementations.

You will own end-to-end technical architecture, design multi-agent workflows for extraction, transformation, validation, and explanation of

Qualifications

• Deep experience designing and delivering GenAI/LLM systems beyond proof-of-concept prompting.
• Hands-on experience with agent orchestration, tool use, structured outputs, retrieval, and evaluation.
• Strong API/software-engineering skills, including automated testing.
• Experience designing AI quality measures, failure handling, human-in-the-loop controls, and auditability.
• Ability to lead architecture across AI, data models, line graphs, and enterprise systems.

Responsibilities

• Own the end-to-end technical architecture and engineering roadmap for the prototype.
• Design multi-agent workflows for extraction, decomposition, transformation, validation, comparison, and explanation of complex rule sets.
• Define where generative AI is appropriate and where deterministic code, schemas, constraints, and human approval are required.
• Engineer structured outputs, tool/API contracts, evaluation harnesses, golden datasets, error taxonomies, and regression tests.
• Work closely with the language/data architect so agent outputs conform to the DSL grammar, standard schema, and graph model.
• Create observable background across source evidence, agent transformations, human decisions, and generated artefacts.
• Provide technical leadership across AI, data, SAP, and assurance specialists.

Skills

GenAI/LLM Architecting

Agent Orchestration

Structured Outputs

APIs & Automated Testing

Human-in-the-Loop

Auditability

AI Quality Metrics

Data Modeling

Tools

Neo4j

RDF Graph Data

DSL/Compiler Concepts

Job description

HMRC seeks a Senior AI & Systems Architect to lead the architecture and engineering of an AI-assisted decision-systems prototype. You will design the agentic workflow, evaluation framework and control boundaries that connect authoritative source material to controlled representations, a deterministic language, standard data, and downstream implementations.

You will own end-to-end technical architecture, design multi-agent workflows for extraction, transformation, validation, and explanation of