SerenX

Job Description About SerenX SerenX is building the next generation of portable, autonomous defensive missile systems to protect America and our allies. We're making advanced air defense smaller, more affordable, and accessible to the people who need it. We're an institutionally funded defense technology company performing work on U.S. Department of Defense contracts. Our founding team includes Y Combinator alumni, former Special Operations leaders, and experienced aerospace engineers. We believe in small engineering teams with real ownership. We design, build, test, fly, break things, learn, and build again. The Role We're hiring a Senior Flight Software Engineer to join our founding engineering team and own the real-time embedded software that controls our SX family of missiles. You'll develop a modern, proprietary C++ flight-software architecture, transitioning from our existing flight-control stack to a clean, modular implementation on ARK Electronics flight-computer hardware. This is software that directly interfaces with sensors, estimates vehicle state, executes control loops, commands actuators, and keeps flight hardware operating reliably. You'll work directly with flight computers, oscilloscopes, debuggers, CAN traces, and real flight hardware. You'll write software, prove it on the bench, and take it to the test range. Location: Melbourne, FL - On-site Employment: Full-time Compensation: $145,000-$180,000 + equity Reports to: CTO What You'll Own Architect, implement, and maintain real-time embedded flight software in modern C++. Develop low-level hardware interfaces, sensor drivers, actuator controls, and vehicle communication systems. Implement and maintain attitude/rate control, state estimation, control allocation, vehicle modes, and flight-safety logic. Establish deterministic execution, scheduling, latency budgets, fault handling, and watchdog behavior on resource-constrained hardware. Design reliable interfaces between the flight computer and our NVIDIA Jetson-based mission/autonomy computer. Build modular hardware abstraction layers and reusable flight-software components that support future vehicle platforms. Develop telemetry, flight logging, instrumentation, and diagnostics to make flight behavior observable and reproducible. Build rigorous verification infrastructure using unit tests, simulation, software-in-the-loop (SIL), hardware-in-the-loop (HIL), fault injection, and flight-log replay. Own embedded build systems, firmware deployment, version control, continuous integration, and reproducible flight-software releases. Work alongside mechanical, electrical, controls, and test engineers during bench testing, integration, hover, and full flight testing. Diagnose real-world failures, identify root causes, implement fixes, and personally validate the results on hardware. What We're Looking For 6+ years of embedded or real-time software engineering experience, with substantial C or C++ development on physical hardware. Exceptional candidates with less experience but unusually strong systems ownership are welcome. Deep proficiency in modern C++, memory management, concurrency, synchronization, debugging, and embedded systems architecture. Experience with embedded Linux, RTOS, or bare-metal development, including cross-compilation, drivers, hardware bring-up, and deployment. Experience developing software for real-time control systems, avionics, robotics, autonomous vehicles, motor control, or similarly demanding physical systems. Understanding of feedback control, IMUs, state estimation, sensor fusion, filtering, timing, and actuator interfaces. Experience with CAN, DroneCAN/UAVCAN, serial communications, telemetry, or other embedded vehicle networks. Strong troubleshooting skills and the ability to diagnose problems across the software, electronics, and physical system. Degree in Computer Engineering, Computer Science, Electrical Engineering, Aerospace Engineering, or a related discipline, or equivalent demonstrated engineering experience. Ability to work on-site in Melbourne, Florida and participate directly in hardware integration and field testing. Particularly Valuable Experience Development or significant modification of ArduPilot, PX4, or other flight-control software. ARM Cortex, STM32, ARK Electronics, Pixhawk/Cube, ChibiOS, NuttX, FreeRTOS, Zephyr, or comparable embedded platforms. Flight-control algorithms, attitude/rate loops, EKF estimation, thrust vector control, actuator allocation, and failsafe systems. Ground-up embedded software architecture or migration from legacy/open-source systems. SIL/HIL, automated verification, fault injection, regression testing, and simulation. UAVs, missiles/interceptors, experimental aircraft, spacecraft, autonomous robotics, or other real-world control systems. Active U.S. Government security clearance, particularly Secret, TS, or TS/SCI, preferred for applicable programs. Who Thrives Here You care about what happens between the sensor reading and the actuator command, our vehicle specifically is an inverted pendulum with a 120ms response window before tumbling. Every millisecond matters. Because of the non-linear dynamics of a hovering missile, you need tp understand that passing a unit test is not the same as flying successfully, and you're comfortable debugging the gap between simulation and physical reality. You will be crashing hardware on the range - that's expected. You want to own the architecture, not just contribute tickets to someone else's roadmap. At SerenX, you'll have direct technical responsibility, work alongside the people designing and building the vehicles, and see your software fly. Engineers who want to go further may also have opportunities to travel with our systems to customer sites and field deployments, subject to program and export-control requirements. Write it at your desk. Test it on hardware. Prove it in flight. Field it in the real world. How to Stand Out Show us something you've made move. We encourage applicants to share examples of embedded systems, robotics, flight software, or control systems they've personally designed, programmed, debugged, and tested. Tell us about a difficult hardware/software failure, how you investigated it, what you changed, and how you proved the fix. We value deep engineering ownership and demonstrated technical ability far more than fashionable frameworks or impressive program names. Export Control & Equal Opportunity This position involves access to ITAR-controlled defense articles, source code, and technical data. Candidates must qualify as a U.S. person under 22 CFR 120.62. SerenX is an equal opportunity employer. Employment decisions are based on qualifications, merit, and business needs, without unlawful discrimination based on any legally protected characteristic. Full position details: -flight-software-engineer