Principal Firmware Engineer Edinburgh 12-month contract Paying up to £90p/h (inside IR35) The Opportunity We are seeking a Senior or Principal Firmware Engineer to join a high-performing engineering team delivering advanced digital systems within the Aerospace, Defence, and Security sector. At Senior or Principal level, you will also provide technical leadership, supporting the delivery of work across multiple engineers while contributing to process improvement and best practice development across FPGA/Firmware teams. Key Responsibilities Design and develop innovative VHDL-based FPGA architectures Apply advanced verification techniques using VHDL or SystemVerilog / UVM Work with current FPGA technologies from: Xilinx Intel (Altera) Microsemi (semiconductor manufacturer) Develop and integrate high-speed interfaces, including PCIe, DDR3, Ethernet and JESD Analyse system-level documentation to derive detailed firmware requirements Adopt a structured, methodical approach to the full firmware lifecycle, ideally aligned with standards such as RTCA DO-254 or similar Specify complex timing and area constraints for efficient FPGA place and route Debug firmware designs and support system verification and integration activities Contribute to process enhancements and ways of working across engineering teams Communicate effectively within multidisciplinary teams and stakeholders Essential Skills & Experience Considerable experience designing firmware architecture using FPGA technologies Strong hands-on experience with Xilinx, Intel (Altera), or Microsemi toolchains Experience with fast interfaces such as PCIe, Ethernet, DDR3, JESD Advanced verification experience using VHDL or System Verilog / UVM Proven ability to derive detailed firmware requirements from system-level specifications Experience working within structured firmware processes (e.g., DO-254) Excellent analytical and problem-solving capability Strong communication skills and a collaborative working style Desirable Familiarity with Model-Based Engineering using: MATLAB Simulink Experience leading or mentoring engineers (for Principal level)