Copello Global are seeking an experienced Systems Engineer to join a leading defence organisation in Buckinghamshire on a 6-12 month contract. This role offers the opportunity to contribute to complex, mission-critical programmes within the avionics domain. As a key member of the engineering team, you will be responsible for supporting the end-to-end systems engineering lifecycle — from requirements definition and design through to integration, verification, and validation. Key Responsibilities * Develop and manage system requirements, specifications, and architectures. * Support system design, modelling, and trade-off studies. * Participate in system integration and verification activities. * Collaborate closely with multidisciplinary engineering teams and key stakeholders. * Ensure technical solutions align with safety, regulatory, and performance standards. * Contribute to documentation, reviews, and compliance activities across the lifecycle. Essential Skills & Experience * Proven background in Systems Engineering, ideally across the full lifecycle (concept to verification). * Experience working in an avionics or related defence/aerospace environment. * Strong understanding of systems modelling, requirements management, and interface control. * Familiarity with tools such as DOORS, Enterprise Architect, or equivalent. * Excellent communication and stakeholder engagement skills...