Castelion is seeking motivated Embedded Software Engineer Interns for Fall 2026. You will help design, implement, test, and debug firmware for embedded systems and flight hardware, write and integrate device drivers for sensors and actuators, and bring up new hardware with on-board software. You will collaborate with hardware, GNC, and flight test teams to ensure robust integration and participate in design reviews and hardware-in-the-loop tests. Responsibilities include developing low-level firmware for embedded platforms, testing and debugging interfaces, and documenting work to improve team knowledge. Basic qualifications include pursuing a BS or MS in Computer Engineering, Electrical Engineering, Computer Science, or related technical field; rising junior, senior, or graduate student; strong C/C++ skills; experience with microcontrollers or SoCs (ARM, AVR, MSP430, PIC, etc.); familiarity with bare-metal or RTOS environments; understanding of board bring-up and debugging; familiarity with SPI, I2C, CAN, UART, Ethernet. A U.S. Person status is required due to ITAR regulations. Preferred skills include experience integrating analog/digital hardware with firmware and familiarity with missile systems, defense technology, or aerospace components; interest in a startup environment with high-impact projects. Why Castelion: a mission-driven company where interns contribute meaningfully to program success. This is a unique opportunity to work at the cutting edge of aerospace engineering while developing skills to grow into a future leader in the field. This internship is paid at

Castelion is seeking motivated Embedded Software Engineer Interns for Fall 2026. You will help design, implement, test, and debug firmware for embedded systems and flight hardware, write and integrate device drivers for sensors and actuators, and bring up new hardware with on-board software. You will collaborate with hardware, GNC, and flight test teams to ensure robust integration and participate in design reviews and hardware-in-the-loop tests. Responsibilities include developing low-level firmware for embedded platforms, testing and debugging interfaces, and documenting work to improve team knowledge. Basic qualifications include pursuing a BS or MS in Computer Engineering, Electrical Engineering, Computer Science, or related technical field; rising junior, senior, or graduate student; strong C/C++ skills; experience with microcontrollers or SoCs (ARM, AVR, MSP430, PIC, etc.); familiarity with bare-metal or RTOS environments; understanding of board bring-up and debugging; familiarity with SPI, I2C, CAN, UART, Ethernet. A U.S. Person status is required due to ITAR regulations. Preferred skills include experience integrating analog/digital hardware with firmware and familiarity with missile systems, defense technology, or aerospace components; interest in a startup environment with high-impact projects. Why Castelion: a mission-driven company where interns contribute meaningfully to program success. This is a unique opportunity to work at the cutting edge of aerospace engineering while developing skills to grow into a future leader in the field. This internship is paid at