Electrical Engineer Intern - Fall 2026 (Avionics)

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, 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.  

Electrical Engineer Intern - Fall 2026 (Avionics)

Castelion is seeking motivated and talented Electrical Engineering Interns for Fall 2026. You'll help design, build, and test the electronics and hardware that drive our advanced missile systems. From architecture and schematic design to board bring-up and validation, you'll own real hardware projects alongside experienced hardware, firmware, and systems engineers. You won't be doing throwaway work. Your contributions will directly support rapid prototyping and real-world flight tests.

Key Responsibilities

• Take ownership of circuit board design from specification and architecture through schematic, layout collaboration, bring-up, and validation
• Design and integrate analog and digital circuits, processors, sensors, and power electronics
• Collaborate cross-functionally with PCB layout, firmware, mechanical, systems, and test teams
• Rapidly iterate hardware designs as system requirements mature
• Document design decisions, calculations, schematics, validation results, and learnings clearly
• Support system bring-up, debug, and test campaigns in the lab and on hardware-in-the-loop benches

Basic Qualifications

• Currently pursuing a BS or MS in Electrical Engineering, Computer Engineering, Mechatronics, or a related field
• Strong understanding of analog and digital circuit design principles
• Experience with PCB component selection and schematic design
• Familiarity with PCB bring-up and debugging
• Some exposure to MATLAB, Python, C/C++, or other tools for modeling and analysis
• Basics of serial communication protocols (CAN, Ethernet, SPI, I2C, etc.)
• U.S. Person status required (due to ITAR regulations)

Preferred Skills and Experience

• Prior project or internship experience designing and testing PCBAs for aerospace, robotics, automotive, or other high-reliability applications
• Familiarity with mixed-signal design, power electronics, or RF systems
• Strong interest in working in a startup environment with high-impact projects.

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 Equal Opportunity Employer. We are committed to providing equal employment opportunities to all applicants and employees without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability, genetic information, protected veteran status, or any other characteristic protected by applicable federal, state, or local law. 

Castelion is committed to providing reasonable accommodations to qualified individuals with disabilities throughout the application and hiring process. If you require a reasonable accommodation to complete an application, participate in the interview process, or otherwise participate in the hiring process, please contact [email protected]. Requests for accommodation will be considered on an individual basis and handled in accordance with applicable law. 

Castelion is committed to fostering a workplace where employment decisions are based on qualifications, business needs, and the ability to perform the essential functions of the role, with or without reasonable accommodation. 

EAR/ITAR Requirements 

This position requires access to export-controlled information, and as such, employment (or hiring of a contractor) is contingent upon the candidate’s ability to access all applicable export-controlled information without additional export licensing being required by the Bureau of Industry and Security and/or the Directorate of Defense Trade Controls.