About Poseidon Aerospace: Poseidon Aerospace is reimagining how the world moves goods. We build and operate full-size autonomous cargo aircraft - capable of carrying two tons of payload over a thousand nautical miles. From remote communities to contested logistics operations, our platforms unlock a new cost curve for air freight, making it faster, cheaper, and accessible anywhere it's needed. Headquartered in the San Francisco Bay Area with locations in Washington DC, Oregon, and Maine; we're building something consequential. About the role Avionics is the electrical and electronic hardware on our cargo aircraft, its mission systems, and the ground control station that operates it. As an Avionics Engineer you will help define that architecture and then build it: power systems, flight and mission computers, actuators, sensors, datalinks, wire harnesses, and instrumentation. You will take hardware from block diagram to bench to aircraft, and support it through ground and flight test. Responsibilities • Contribute to the electrical and avionics architecture of the aircraft, mission systems, and ground control station • Design and integrate power generation, storage, and distribution, and maintain the electrical load analysis • Select and integrate flight computers, mission computers, actuators, sensors, radios, and datalinks • Produce system schematics, interface control documents, and wire harness drawings • Support harness fabrication, installation, and checkout on the aircraft • Configure and troubleshoot data buses (CAN, ARINC 429, RS-232/485, Ethernet) • Design grounding, bonding, and shielding to control EMI/EMC • Specify and install flight test instrumentation and data acquisition hardware • Build and maintain bench and hardware-in-the-loop test setups • Write and run acceptance and functional test procedures for avionics hardware • Troubleshoot hardware on the aircraft during ground and flight test, including travel to our flight test site • Work with flight software, GNC, airframe, propulsion, and flight test on interfaces and installation Required Qualifications • B.S. in electrical engineering, aerospace engineering, or a related field, or equivalent experience • 2+ years designing or integrating electrical and electronic systems on vehicles (aircraft, UAS, spacecraft, or automotive) • Proficiency with schematic capture or harness design tools such as Altium, AutoCAD Electrical, or Capital • Hands-on experience debugging hardware with multimeters, oscilloscopes, and logic analyzers • Working knowledge of power distribution, grounding, and common vehicle data buses Preferred Qualifications • Avionics experience on crewed or uncrewed aircraft • Wire harness design and fabrication to aerospace standards such as AS50881 • Familiarity with DO-160, DO-254, MIL-STD-704, or MIL-STD-461 • Experience integrating antennas, GPS, radios, or datalinks • Experience with electromechanical actuators or motor controllers • Experience with flight test instrumentation and data acquisition systems • PCB design for breakout boards or signal conditioning • Python for test automation and data analysis • Private pilot certificate or Part 107 certificate Why this role Avionics connects every system on the aircraft: power, propulsion, flight controls, mission systems, and the link to the ground. You will design hardware, build it, install it, and see it fly on an aircraft that carries two tons. What you get from us • Competitive salary and meaningful early-stage equity • Relocation support if applicable • Employee Health Benefit Plans • 6% Retirement matching • Flexible PTO • Free lunches, snacks, and a stocked fridge at our offices • AI tools and subscriptions