Location: Commutable to Herfordshire, Cheltenham, and Bristol — mostly on-site (4 days/week on customer site, 1 day remote where appropriate) Clearance: Must be eligible and willing to undergo DV clearance (British Citizen, UK residency last 10 years) Are you a proven embedded software engineer who thrives on hard problems and real-world constraints? Want to design and deliver operational tooling directly alongside end users in National Security & Defence? We’re looking for a senior technical contributor who can take ownership of embedded deliveries, guide technical direction, and mentor others—working across ESP32, Raspberry Pi, and ARM platforms. What You’ll Do • Lead development of bespoke embedded solutions across multiple platforms. • Design, implement, and maintain production-quality C, C++ and/or Python code interfacing with hardware. • Architect solutions involving comms protocols, peripheral integration, and performance/robustness constraints. • Lead debugging, testing, and optimisation across lab and field environments. • Shape requirements with stakeholders; propose approaches and influence delivery plans. • Support integration, configuration, and deployment into secure operational environments. • Produce high-quality documentation and enforce consistent Git workflows and review standards. • Mentor junior engineers and raise team capability through coaching and knowledge sharing. What You’ll Bring Essential: • Extensive hands-on embedded software development experience. • Strong proficiency in C/C++ (and/or Python where appropriate). • Deep experience with embedded systems (ESP32, ARM Cortex, SBCs). • Strong understanding of low-level interfacing (UART, GPIO, USB, SPI/I2C). • Confident in Linux-based development environments and toolchains. • Strong debugging skills (JTAG/SWD, logic analysers, profiling, etc.) and disciplined engineering practice. • Ability to communicate clearly and influence technical decisions across teams. Desirable: • Experience delivering in secure/defence environments. • Knowledge of cryptography, secure transport, or secure system design. • Wireless experience (Bluetooth, UWB, Wi-Fi). • USB device drivers / advanced USB comms. • RTOS / bare-metal expertise. • Embedded Rust experience or strong interest. Education & Qualifications • Degree in a relevant discipline preferred (or equivalent experience). • Professional membership (BCS, IET) is a plus. Clearance Requirements: • Clearance to Start: SC • Clearance for Role: DV What we do for you: At Leidos we are PASSIONATE about customer success, UNITED as a team and INSPIRED to make a difference. We offer meaningful and engaging careers, a collaborative culture, and support for your career goals, all while nurturing a healthy work-life balance. We provide an employment package that attracts, develops and retains only the best in talent. Our reward scheme includes: • Contributory Pension Scheme • Private Medical Insurance • 33 days Annual Leave (including public and privilege holidays) • Access to Flexible benefits (including life assurance, health schemes, gym memberships, annual buy and sell holidays and a cycle to work scheme) • Flexi-Time