System Hardware Engineer (Autonomous Flight Termination)

Castelion was founded to restore America’s ability to field advanced weapons at speed and scale. Inspired by the engineering urgency of the WWII and Apollo eras, we combine rapid iteration, vertical integration, and scalable manufacturing to deliver affordable, high-performance strike systems. Our mission: rebuild industrial agility to strengthen national security and outpace evolving threats.

About the Role

We are seeking a Senior Autonomous Flight Termination System (AFTS) Hardware Engineer to design and deliver high-reliability flight safety electronics for Castelion's long-range hypersonic strike vehicles. This role is critical to ensuring safe, deterministic vehicle termination through robust, fault-tolerant hardware.

You will work hands-on with multidisciplinary engineering teams to design, build, test, and validate pulsed power electronics and firing systems, with a focus on electronic safe and arm devices (ESADs) and related architectures in a fast-paced, hardware-driven environment.

Requirements

Bachelor's, Master's, or PhD in Electrical Engineering or related field 5+ years of experience designing and validating pulsed power, high-voltage, or firing system electronics for aerospace, defense, or similar high-reliability applications Strong background in energy storage, high-speed/high-current switching, and pulsed power circuit design Experience with electronic safe and arm devices (ESADs), initiation systems, or similar safety-critical hardware Proficiency in circuit design, simulation, and analysis tools (e.

g., SPICE, MATLAB/Simulink, or equivalent) Experience with hardware bring-up, environmental testing, and troubleshooting in a lab or flight hardware environment Familiarity with system safety, redundancy, and fault-tolerant design principles for mission-critical systems Experience designing for EMI/EMC, thermal performance, and operation in extreme environments Strong problem-solving mindset, thriving in a fast-paced, hardware-rich, high flight cadence environment Benefits Employee Equity: Meaningful equity for all full-time employees - share value has increased 150x in three years Personal Time Off: Four (4) weeks of paid time off to unplug, reset, and come back sharp—velocity matters, burnout doesn't Company Paid Holidays: Ten (10) company paid holidays Medical: We offer plans at 100% employee covered and 80% of dependent coverage Dental & Vision: We cover 90% employees and 80% for dependents to ensure you and your family have access to quality preventive and ongoing care FSA/HSA: To support long-term health and financial resilience, we offer FSA and HSA options that allow employees to set aside pre-tax dollars for eligible medical and dependent care expenses Retirement: 401k plan offered to support long term financial growth along side high-impact, high-velocity work Paid Parental Leave: We support growing families with meaningful time to bond and recover.

Birthing parents are eligible for up to 10 weeks of paid leave, while non-birthing parents may take up to 4 weeks of paid leave. This time can be used for pre-natal care, pregnancy, childbirth, and related medical needs—ensuring every parent has the support they need during this important life moment.8-weeks of paid parental leave for all parents.

Additional paid pregnancy leave for CA employees Meals & Catering: Frequently catered lunches and team meals, plus company-covered meals when extra time or effort is required Snacks & Beverages: Fully stocked kitchen with unlimited snacks and drinks to keep you fueled throughout the day Performance & Fitness: $100 monthly fitness stipend to support peak performance and health, both inside and outside of work EV Charging: Onsite electric vehicle charging available for employees