Senior Power Electronics Engineer

Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus, ownership, and excellence are decisive advantages - and we're building a world-class team to turn bold ideas into real capability.

This is a rare opportunity to join at an early stage, where you'll have significant ownership, collaborate with exceptional teammates, and make a direct, measurable impact on our mission and the future of the company - regardless of your function.

We are seeking a Senior Power Electronics Engineer to develop and integrate advanced electrical power systems for Castelion's long-range hypersonic strike vehicles. This role is critical to ensuring reliable power generation, storage, and distribution across mission-critical avionics and vehicle subsystems. You will...

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

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
Castelion offers a generous benefits package. Please refer to the bottom of our Careers page for more details.  
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. 
Additional Eligibility Requirements 
This position may require access to classified information or restricted U.S. Government sites, systems, or information, as determined by the Company and/or applicable U.S. Government requirements. If the position is so designated, your employment in the role may be contingent upon your ability to obtain and maintain the required U.S. Government security clearance or other government authorization, and to satisfy any citizenship or other eligibility requirements imposed by applicable law, regulation, executive order, or government contract requirements. You will be notified if and when such requirements apply. 
Affirmative Action/EEO Statement 
Castelion is an

Citizen