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 Test and Validation finds problems on the ground before they show up in flight. As a Senior Test and Validation Engineer you will own how Poseidon does that. You will define the hardware-in-the-loop and simulation architecture, the validator framework, and the system test roadmap, and decide what gets tested at the component level, on the bench, on the aircraft, and in flight. You will build much of it yourself and lead the engineers and technicians who run it. RESPONSIBILITIES - Own the system test roadmap and the strategy for what is tested at component level, in hardware-in-the-loop, in ground test, and in flight test - Architect and bring up hardware-in-the-loop benches with flight computers, actuators, sensors, and power hardware in the loop - Own the simulation infrastructure, including software-in-the-loop, real-time simulation, and integration of models from GNC and flight sciences - Define the validator framework and the criteria a software or hardware release must meet before it goes on the aircraft - Design fault injection and rapid fault-finding campaigns driven by the vehicle failure mode analysis - Work with flight software to define the test-mode features needed in flight code - Turn mission profiles into qualification and life-test plans, including stress levels and test duration - Develop new ways to reproduce flight loads and environments on the ground, and correlate test conditions to flight data - Develop health monitoring and anomaly detection from vehicle telemetry for use in test and on the aircraft - Lead environmental and durability test campaigns, including outside test labs - Present test evidence at flight readiness reviews and support certification evidence - Lead root cause investigations on faults found in test - Lead and mentor test engineers and technicians REQUIRED QUALIFICATIONS - B.S. in electrical, mechanical, aerospace, or computer engineering, or a related field, or equivalent experience - 5+ years testing complex electromechanical or embedded systems on aircraft, spacecraft, automotive, or comparable vehicles - Architected and brought up a hardware-in-the-loop or system test capability from scratch - Owned the test strategy for a hardware and software program through to fielded operation or flight - Planned and ran environmental, durability, or reliability test campaigns that changed engineering decisions - Strong software skills in Python and C or C++ - Strong electrical troubleshooting skills across embedded computers, actuation, power, and communications - Led test engineers or technicians PREFERRED QUALIFICATIONS - Test experience on uncrewed aircraft or fly-by-wire aircraft - Experience with real-time simulation platforms such as Speedgoat, dSPACE, or NI - Experience with reliability methods including FMEA, Weibull analysis, and accelerated life testing - Experience qualifying hardware to DO-160 or MIL-STD-810 - Experience building an iron bird or full-vehicle integration rig - Experience developing real-time controls for safety-critical systems - Experience with test evidence for certification or military airworthiness WHY THIS ROLE Every flight software release and every avionics box will pass through what you build before it reaches the aircraft. The test capability here is still being defined, and you will define it. How well you do it sets how fast the program can fly safely. 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