Senior Power Electronics Engineer

About the role

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.

Responsibilities

• 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
• Partner closely with program leadership to make technical trades aligned with mission success

Qualifications

• Bachelor's, Master's, or PhD in Electrical Engineering or related field
• 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 (e.g., 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
• Strong problem-solving mindset, thriving in a fast-paced, hardware-rich, high flight cadence environment
• Ability to obtain and maintain a U.S. government–issued security clearance
• U.S. citizenship required

Benefits

• Meaningful long-term equity for all full-time employees
• Four (4) weeks of paid time off
• Ten (10) company-paid holidays
• Comprehensive health benefits – including 100% employee-covered medical and strong dependent coverage, plus dental and vision plans
• Paid parental leave
• $100 monthly fitness stipend
• Onsite EV charging
• Catered meals, company-covered food during high-demand periods, fully stocked kitchen