Principal Software Engineer

Principal Software Engineer – Mission-Critical Platforms (Java / React) 📍 On-Site | 💷 Salary Competitive 🧳 Relocation Assistance Available | UK Citizenship Required 🔐 Must Hold UK-Highest Level Security Clearance Lead a team delivering secure, high-impact software solutions for national defence. My client is seeking a Principal Software Engineer to oversee the design, development, and delivery of complex software systems across defence, security, and intelligence domains. You’ll combine hands-on engineering with technical leadership, guiding a multidisciplinary team through agile delivery while maintaining technical excellence. This is a leadership role for someone passionate about building stable, elegant solutions in a mission-critical environment, with the autonomy and backing to make meaningful decisions that impact national security. 🔧 What You’ll Do :

• Own team deliverables, working alongside the Scrum Master to meet mission and delivery goals
• Lead technical design, code development, testing and deployment of secure, scalable systems
• Guide and mentor junior developers, setting engineering standards and fostering growth
• Collaborate with front-end engineers, DevOps, and QA teams to integrate full-stack solutions
• Engage directly with stakeholders to shape outcomes based on real-world needs ✅ What You’ll Bring :
• Hands-on experience as a Senior or Lead Software Engineer
• Specialism in backend Java (Spring Boot, Maven) or frontend React (Node, npm)
• Proven record designing and deploying robust systems in secure environments
• Familiarity with CI / CD, containerisation, and cloud-native tools : Jenkins, Docker, Kubernetes, AWS
• Strong collaboration, communication, and Agile working practices
• UK highest level of government clearance (active and current) 🧭 Why Join?
• A mission-driven team solving the most complex engineering challenges in defence and intelligence
• 9-day fortnight available (every other Friday off)
• Private healthcare, bonus schemes, career pathways Inclusive environment with leadership who invest in your development