Principal Software Engineer

About the role

Join a leading defence technology team to design, architect and deliver secure embedded and application software for advanced cyber and defence programmes. You will work across the full software lifecycle in a highly regulated environment, contributing to projects that protect lives and national security.

Key responsibilities

• Architect, design, develop and test embedded and application software, ensuring high‑quality and timely deliverables.
• Apply object‑oriented design techniques to enable efficient code reuse and integration with testing frameworks.
• Review system design artefacts to derive software requirements and align architecture with system objectives.
• Maintain best practices in software development, including TDD/BDD, DevSecOps and secure coding standards.
• Mentor junior engineers, provide technical leadership and improve tools, processes and techniques.
• Generate technical proposals and accurate estimates for bids and projects, ensuring cost and schedule adherence.

Required profile

• Degree in engineering, mathematics, a science‑based subject or equivalent.
• Strong experience in C/C++ and embedded systems.
• Proven experience with software engineering best practices.
• Eligibility for UK security clearance.
• Experience working in highly regulated environments.

Required skills

• C/C++
• Embedded systems
• Object‑oriented design
• DevSecOps
• Test‑Driven Development (TDD) / Behaviour‑Driven Development (BDD)
• Secure coding standards
• Continuous integration
• Software architecture

What we offer

• Private medical cover
• Flexible working hours
• Annual bonus scheme