Embedded Software Engineer Intern - Fall 2026 at Castelion in Torrance, CA
- Company: Castelion
- Location: Torrance, CA
- Posted: Sep 17, 2026
- Type: Internship
Overview
Castelion is seeking motivated and talented Embedded Software Engineering interns for Fall 2026. You'll help create the software that drives and simulates our missile systems, from low-level firmware on microcontrollers to high-level integration and testing tools. You'll work alongside experienced e…
Job description
- Castelion is seeking motivated and talented Embedded Software Engineering interns for Fall 2026. You'll help create the software that drives and simulates our missile systems, from low-level firmware on microcontrollers to high-level integration and testing tools. You'll work alongside experienced embedded, hardware, and flight systems engineers to design, implement, test, and debug real systems in the loop.
- You won't be writing throwaway code; your contributions will directly support our rapid prototyping and real-world tests.
Responsibilities
- Develop, test, and debug low-level firmware for embedded systems and flight hardware
- Write and integrate device drivers for sensors, actuators, and missile subsystems
- Bring up new hardware, test boards, and debug at the intersection of electrical and software layers
- Collaborate cross-functionally with hardware, GNC, and flight test teams to ensure robust integration
- Participate in design reviews, hardware-in-the-loop tests, and on-the-bench bring-up and validation
- Document your work clearly and share learnings to improve team knowledge and future designs
Requirements
- Currently pursuing a BS or MS in Computer Engineering, Electrical Engineering, Computer Science, or a related technical field
- Rising junior, senior, or graduate student at the time of the internship
- Strong C/C++ programming skills for embedded systems
- Experience with microcontrollers or SoCs (ARM, AVR, MSP430, PIC, etc.)
- Familiarity with developing in bare-metal or RTOS environments
- Understanding of board bring-up and debugging fundamentals
- Some familiarity with common protocols: SPI, I2C, CAN, UART, Ethernet, etc.
- U.S. Person status required (due to ITAR regulations)
- Experience integrating analog/digital hardware with firmware
- Familiarity with missile systems, defense technology, or aerospace components.
- Strong interest in working in a startup environment with high-impact projects.
Skills
Required
- Motivated
- Talented
- Collaborative
- C/C++
- Microcontrollers
- SoCs (ARM, AVR, MSP430, PIC)
- Bare-metal development
- RTOS
- SPI
- I2C
- CAN
- UART
Benefits
- Castelion offers a generous benefits package. Please refer to the bottom of our Careers page for more details.
About Castelion
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.