Step into a world where innovation meets impact. This Principal Software Engineer role offers you the chance to be a part of cutting-edge defence technology, driving advancements that redefine security and protect lives. Working in a dynamic and collaborative environment, you''ll lead projects that make a real difference, while enjoying excellent benefits such as private medical cover, flexible working hours, and participation in an annual bonus scheme. If you''re ready to shape the future of defence systems by leading the design, architecture, and delivery of secure embedded and application software within advanced cyber and defence programmes. You ll work across the full software lifecycle from requirements and system design through to implementation, testing, and deployment while ensuring high standards in performance, security, and reliability. The position includes technical leadership of small engineering teams, mentoring junior developers, and contributing to multiple concurrent projects with varying scales and complexity. You ll apply modern development practices such as object-oriented design, DevSecOps, and continuous integration, while also supporting bids, cost estimation, and technical reviews. Strong experience in C/C++, embedded systems, and software engineering best practices is essential. The role requires working in highly regulated environments, including handling sensitive information and meeting strict security standards. Candidates must be eligible for U