Why Castelion, Why Now

Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus and technical excellence are decisive advantages - and we are building a team that can deliver real capability, not just concepts.

This is a rare opportunity to join at an early stage, where your work will directly shape critical systems, influence major technical decisions, and have immediate, real-world impact.

Senior Autonomous Flight Termination System Hardware Engineer

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.

Responsibilities

• Design and develop pulsed power electronics for flight termination and firing systems, including high-voltage energy storage, switching, and delivery circuits
• Lead the architecture and implementation of electronic safe and arm devices (ESADs) and related safety-critical hardware
• Develop robust initiation and firing circuits, ensuring deterministic performance, redundancy, and fault tolerance
• Work closely with avionics, GNC, flight software, and systems engineering teams to ensure seamless integration of AFTS hardware with vehicle systems
• Perform circuit-level and system-level modeling and analysis to validate performance, timing, and reliability under dynamic flight conditions
• Define and execute qualification, environmental, and flight test plans, translating results into system-level improvements
• Support hardware bring-up, integration, and test campaigns, including debugging, failure analysis, and root cause investigation
• Ensure compliance with safety, range, and mission assurance requirements for flight termination systems
• Mentor junior engineers and contribute to best practices in high-reliability pulsed power and safety-critical electronics design
• Partner closely with program leadership to make technical trades aligned with mission success

Basic Qualifications

• 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

Other Duties

Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee for this job. Duties, responsibilities and activities may change at any time with or without notice.

Benefits And Perks

All full-time employees are granted meaningful long-term equity, sharing in the company's significant growth trajectory. We offer four (4) weeks of paid time off, ten (10) company-paid holidays, and comprehensive health benefits - including 100% employee-covered medical and strong dependent coverage, along with dental and vision plans. We also provide paid parental leave to support growing families, a $100 monthly fitness stipend to promote health and performance, and onsite EV charging for convenience. In addition, employees enjoy perks like catered meals, company-covered food during high-demand periods, and a fully stocked kitchen to stay fueled throughout the day.

While this position does not currently require a U.S government-issued security clearance, it may in the near future. Therefore, the ability to obtain and maintain a U.S. government–issued security clearance is required. U.S. citizenship is required, as only U.S. citizens are eligible for a security clearance.

Affirmative Action/EEO Statement

Employment with Castelion is governed on the basis of competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.