Onsite / Hybrid | Start-up | Unmanned Aircraft Programme No visa sponsorship is available. Applicants must already have the right to work in the UK. A fast-growing start-up is looking for a senior, hands-on engineer to lead the design, integration and troubleshooting of avionics and onboard systems for a flagship unmanned aircraft programme, plus future product and customer developments. You'll sit within a growing systems engineering function, working closely with senior engineering leadership, while staying heavily involved in practical integration across avionics, comms, power, autopilot and payload/ground interfaces. What you'll be doing Design, integrate and troubleshoot UAS avionics and onboard systems Define avionics architecture, interfaces, power distribution, wiring and communications requirements Support autopilot, telemetry, GNSS/INS, payload interfaces and ground-control integration Produce and maintain interface documents, wiring diagrams, configuration records and test evidence Support requirements capture, integration planning, ground test, SIL/HIL and flight test activities Identify and resolve integration risks and system-level issues Improve repeatability and maturity (documented, testable, supportable systems) and help productise integration approaches What we're looking for (essential) Strong background in UAS / aerospace / avionics / robotics / embedded systems / mechatronics Experience integrating avionics, communications, autopilots and/or payload interfaces Practical understanding of wiring, power and data interfaces, and HW/SW integration Confident fault-finding on complex integrated systems Test support experience (ground, field and/or flight test) Strong documentation and configuration-control habits Comfortable working hands-on in a small, fast-growing technical team Nice to have PX4, ArduPilot, Auterion (or similar) MAVLink, CAN, Ethernet, serial, GNSS/INS, telemetry, RF SIL/HIL testing exposure Aerospace/defence/robotics/autonomy background Awareness of safety/airworthiness/regulated test environments