Principal Software Engineer Location: Edinburgh, United Kingdom Contract Duration: 12 months Rate: £63.83 p/h PAYE (£73.11 inc. holiday rate) OR £87.04 p/h UmbrellaWe seek an engineer with recent high-integrity or safety-critical industry experience (defence, aerospace, or similar), or eligible for UK security clearance. Role OverviewAn experienced Principal Software Engineer is required to join a well-established Test Engineering community, supporting advanced defence and aerospace programmes. The role focuses on developing software solutions for complex test systems used in cutting-edge radar and aerospace platforms.The successful candidate will play a key technical leadership role, contributing to the design, development, and delivery of high-quality test software while working closely with multi-disciplinary engineering teams and stakeholders. Key Responsibilities Design, develop, and deliver software solutions within defined work packages, ensuring stakeholder requirements are metElicit, analyse, prioritise, and manage stakeholder needs to deliver optimal technical solutionsProduce high-quality, robust, and well-documented code, ensuring outputs are maintained under configuration managementProvide progress reporting, planning, and technical updates to line managementCollaborate with internal and external stakeholders to ensure software architecture alignment across the wider programmeApply appropriate tools and techniques for test equipment and test system software desig