We''re looking for an experienced Enterprise Architect for our client to play a pivotal role in shaping and delivering mission-critical systems across sectors such as defence, central government, energy, and transport. This is a unique opportunity to work at the forefront of national infrastructure, ensuring systems are secure, resilient, and fully interoperable in high-stakes environments. The Role As a key technical authority, you''ll take ownership of the end-to-end architecture life cycle - translating complex stakeholder requirements into high-integrity technical solutions. You''ll be working on large-scale, safety-critical programmes, influencing architecture across systems of systems environments. What You''ll Be Doing Deriving detailed use cases from complex mission and stakeholder requirements Developing logical and physical data models (UML/SysML) Producing and managing Interface Control Documents (ICDs) Creating Software Requirements Specifications (SRS) and technical design artefacts Embedding cyber resilience and security-by-design principles Collaborating across multi-disciplinary teams (Cyber, Software, Engineering) What We''re Looking For Strong experience as an Enterprise Architect/Systems Architect Expertise in MBSE tools (Cameo, IBM Rhapsody) Experience working within complex, regulated environments Understanding of frameworks such as ISO 15288, NIS Regulations, Gov Tech Codes of Practice Proven ability to lead across ..... full job details .....