Senior System Engineer | up to £80,000 | Farnborough - Hybrid We are seeking a Senior System Engineer to join a high-profile government defence programme, working on systems vital to national security. This role offers the opportunity to work across the full engineering lifecycle in an agile environment, with a focus on Model-Based Systems Engineering (MBSE) and secure systems delivery. Key Responsibilities: * Work with stakeholders, suppliers, and architects to define system-of-systems requirements. * Use MBSE tools to model functional requirements and system behaviours. * Lead technical derivation, compliance assessments, and requirements allocation. * Produce detailed engineering artefacts including designs, failure modes analysis, security documentation, and service management designs. * Support onboarding of services onto virtualised infrastructure. * Conduct system-level cost/benefit and technical trade studies. * Deliver milestone reviews and ensure engineering tasks align with programme scope. * Define and model interfaces, user scenarios, and security requirements. * Collaborate across agile teams to maintain design and architectural alignment. Required Skills & Experience: * Strong expertise in architecture modelling tools (e.g. Sparx EA, MagicDraw Cameo). * Familiarity with frameworks and languages such as TOGAF, MODAF, NAF, SysML, Archimate. * Experience on large-scale, mission-critical integration programmes. * Skilled in system modelling, interface definition, and functional decomposition. * In-depth knowledge of requirements engineering (text and model-based). * Experience with secure systems design, including CIA principles and virtualised environments. * Strong stakeholder and supplier coordination abilities. * Proven ability to develop security artefacts (e.g. RMADs, SyOPS, ISMS, DART). * Minmum SC cleared, ideally DV cleared. Desirable: * ITIL and knowledge of Service Management processes. * Background in Air Traffic Management or other safety-critical domains. * Experience with assurance and regulatory compliance across functional areas. * Willingness to challenge conventions and offer innovative solutions. * Confident communicator with clear written and verbal presentation skills. This is a rare opportunity to play a key role in a strategically significant programme, delivering secure, high-assurance systems that make a real-world impact. If you thrive in complex, fast-paced engineering environments, we'd love to hear from you.