Job Title: Principal Systems Engineer (Facilities & Infrastructure Upgrades)Location: AmesburyWFH: 3 days onsite per weekDuration: 6 monthsClearance: SC to Start preferredIR35: InsideDay Rate: £DOEKey Skills: Systems Engineering, Test, Trials, Training, Infrastructure, Engineering, Rail, Nuclear, Aviation, Military, Full Lifecycle, RIBA, CDM, JCT, NECAbout the RoleWe are seeking an experienced Principal Systems Engineer to lead the technical delivery and systems engineering of complex, high-value infrastructure projects supporting Test, Trials, Training and Evaluation. This includes facilities and infrastructure that supports the testing of aviation, land, and environmental systems.In this role, you will act as the Technical Lead and Lead Systems Engineer, guiding projects from requirements through to transition to service, while mentoring junior engineers and providing technical advice across multiple programmes. You will be responsible for ensuring solutions are compliant, safe by design, and delivered to time, cost, and quality standards.Key Responsibilities as a Principal Systems Engineer:Lead technical delivery of complex systems programmes or multiple infrastructure projects.Develop systems engineering artefacts throughout project lifecycle, including Technical Delivery Plans, Stakeholder & System Requirements, Architecture Design Documents, Integrated Test & Evaluation Plans, and Acceptance Plans.Lead tailoring of project lifecycles and engineering governance approaches, advising and mentoring others.Oversee subcontracted technical activity, ensuring risk transparency, mitigation, and compliance.Identify, manage, and mitigate critical safety, security, and high-risk elements early in the lifecycle.Plan complex installation, integration, and acceptance activities across multidisciplinary teams and stakeholders.Required Skills & Experience as the Principal Systems Engineer:Experience delivering facility and building upgrades using systems engineering processes.Proven ability to lead high-value technical programmes through the full project lifecycle.Experience in specialist infrastructure sectors such as:Defence / military (ex-forces experience beneficial)Aviation facilities and test rangesUK nuclear sitesRailways or critical industrial infrastructureStrong knowledge of systems integration including facilities, equipment, control, communication, and IT systems.Have a deep understanding of engineering standards, RIBA stage gates, regulatory compliance, and safety-critical functions.Experience managing multidisciplinary engineering teams and multiple stakeholders across complex projects.Have strong leadership, mentoring, and coaching skills with excellent communication at all levels.QualificationsDegree in Systems Engineering, Engineering, or relevant technical discipline Chartered Engineer (CEng) or equivalent idealDemonstrable track record of hands-on delivery of systems engineering artefacts and leading teams in complex technical programmes.***PLEASE NOTE***Security Clearance (SC) or eligibility to gain is required to be considered for this vacancy