Senior Flight Software Engineer

Poseidon AerospacePoseidon 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 RoleFlight software is the code that runs on the flight computers of our autonomous cargo aircraft. As a Senior Flight Software Engineer you will own major parts of that software, from architecture through flight test. You will decide how the software is structured, how it handles failures, and how it is tested, and you will write a large share of the code yourself. You will also set the technical bar for the engineers around you.ResponsibilitiesOwn the architecture of major flight software subsystems, including timing, partitioning, and redundancyDesign and implement deterministic, real-time embedded flight software in C++Design fault detection and response for the aircraft, including redundancy management, degraded modes, and lost-link behaviorDefine software requirements and interfaces with avionics, GNC, and flight test, and trace them to testsImplement the GNC team's algorithms in flight code and verify them against simulationSet the test strategy across unit tests, software-in-the-loop, and hardware-in-the-loopBuild telemetry, logging, and command paths between the aircraft and the ground stationLead software integration on the aircraft and support ground testing and flight test, including travel to our flight test siteSet coding standards and review practices, and lead design reviewsMentor other flight software engineersRequired QualificationsB.S. in computer science, engineering, or a related field, or equivalent experience5+ years of professional C or C++ development on embedded, real-time, or safety-critical systemsOwned a flight software subsystem or equivalent from architecture through fielded operationTook software through hardware integration and test on a real vehicle (aircraft, spacecraft, or automotive)Designed fault detection and response for a system where failure had safety consequencesLed design reviews and set technical direction for other engineersPreferred QualificationsFlight software experience on crewed or uncrewed aircraft, or on spacecraftRTOS or bare-metal development, with a deep understanding of scheduling, timing, and memoryExperience designing redundant or fault-tolerant flight computer architecturesExperience developing software under DO-178C or a comparable standard such as ISO 26262Experience supporting flight test or vehicle test campaignsPython for tooling, test automation, and flight data analysisClear technical writingWhy This RoleFlight software touches every system on the aircraft: avionics, propulsion, flight controls, and the ground station. You will make the decisions that shape how those systems work together, at a stage where the architecture is still yours to set. You will work directly with flight hardware and watch your code fly an aircraft that carries two tons.What You Get From UsCompetitive salary and meaningful early-stage equityRelocation support if applicableEmployee Health Benefit Plans6% Retirement matchingFlexible PTOFree lunches, snacks, and a stocked fridge at our officesAI tools and subscriptions