Senior Power Electronics Engineer

About Castelion

Castelion is bringing a new approach to defense development and production: short, iterative design cycles, rapid testing in development, and modern commercial manufacturing strategies for production at scale. The company is designing, building, and testing next-generation long-range strike weapons systems to give America and its allies a definitive edge and deter future conflicts.

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

The Opportunity

Castelion is looking for a Senior Power Electronics Engineer to develop and integrate advanced electrical power systems for long-range hypersonic strike vehicles. You will work hands-on with multidisciplinary engineering teams to design, analyze, test, and validate power electronics hardware in a high flight cadence, hardware-driven environment.

This role is critical to ensuring reliable power generation, storage, and distribution across mission-critical avionics and vehicle subsystems. You will lead the design of battery architectures, power controllers, and power management systems, working directly with avionics, GNC, and flight software teams to ensure seamless integration across all mission phases.

What You’ll Do

• •      Design and develop power electronics systems including battery architectures, power conversion, and distribution for high-performance flight vehicles
• •      Lead the design and optimization of power controllers and power management systems to ensure stable, efficient operation across all mission phases
• •      Develop and analyze battery systems including selection, packaging, thermal considerations, and safety mechanisms for demanding environments
• •      Work closely with avionics, GNC, and flight software teams to ensure seamless integration of power systems with vehicle subsystems
• •      Conduct circuit-level and system-level modeling and simulation to evaluate performance, efficiency, and reliability under dynamic conditions
• •      Support hardware bring-up, integration, and test campaigns including troubleshooting and root cause analysis
• •      Define and execute qualification and flight test plans, translating results into system-level improvements
• •      Mentor junior engineers and contribute to best practices in power electronics design

You Should Have

• •      5+ years of experience in power electronics design, analysis, and validation for aerospace, defense, or other high-reliability systems
• •      Strong background in battery systems, power conversion (DC-DC), and power distribution architectures
• •      Experience designing power controllers and power management systems for embedded or avionics applications
• •      Proficiency in circuit design, simulation, and analysis tools such as SPICE, MATLAB/Simulink, or equivalent
• •      Experience with hardware bring-up, test, and troubleshooting in a lab or flight hardware environment
• •      Familiarity with thermal management, EMI/EMC considerations, and ruggedized electronics design
• •      Bachelor’s, Master’s, or PhD in Electrical Engineering or a related field
• •      U.S. citizenship required; ability to obtain and maintain a U.S. security clearance

Compensation and Benefits

Meaningful long-term equity for all full-time employees. Benefits include comprehensive medical coverage (100% employee-covered, strong dependent coverage), dental and vision plans; paid parental leave; four weeks of paid time off; ten company-paid holidays; $100 monthly fitness stipend; catered meals and a fully stocked kitchen; and onsite EV charging.