Principal Software Engineer

🚀 Senior / Principal Software Engineer 📍 Berkshire | 🏢 Permanent | On-site Build secure software. Solve complex problems. Shape next-generation defence technology. Copello are partnering with a leading defence and cyber organisation in Berkshire to find an experienced Senior/Principal Software Engineer to join a highly skilled engineering team. This is a fantastic opportunity for a software engineer who enjoys technical ownership, complex problem-solving and hands-on development, working on secure, mission-critical products across embedded and application environments. 💻 The Role You’ll take technical responsibility across the software development lifecycle — from requirements and architecture through to design, implementation, testing and verification. You’ll be involved in: Designing and developing embedded and/or application software. Working with C and C++ across bare-metal, RTOS and Linux environments. Developing robust, reusable software using Object-Oriented Design and SOLID principles. Supporting software architecture, requirements and technical design. Driving best practice across TDD/BDD, CI, DevSecOps and automated testing. Working closely with Systems, Hardware and Firmware engineers. Leading technical reviews and contributing to key engineering decisions. Mentoring and supporting less experienced engineers. Contributing to technical proposals, bids and future product development. Driving improvements in software tools, processes and engineering practices. 🎯 What we're looking for We’re keen to speak with experienced Software Engineers who have: ✔ Strong C/C++ experience ✔ Significant experience in embedded software development ✔ Experience with bare-metal, RTOS and/or Embedded Linux ✔ Strong understanding of software development lifecycles and best practice ✔ Experience with Object-Oriented Design and Design Patterns ✔ Strong software testing and design-for-test experience ✔ Experience working in complex or regulated environments Knowledge of Rust, TCP/IP, MISRA, DevSecOps, CI/CD, DOORS, UML, SysML or Enterprise Architect would be advantageous. 🌟 Why this opportunity? You’ll be working on secure, mission-critical technology within a highly technical defence environment, with the opportunity to influence architecture, develop your technical expertise and mentor the next generation of engineers. The role offers a strong benefits package, including bonus, private medical, enhanced pension, 25 days' holiday + bank holidays, flexible benefits and a potential early Friday finish. 🔐 Security clearance: Candidates will need to be eligible to obtain and maintain SC and DV clearance. If you’re a Senior Software Engineer, Principal Software Engineer, Embedded Software Engineer or Technical Lead looking for your next challenge, get in touch. 📞 Victoria – [phone removed] 📧 [email removed]