Flight Software Engineer Intern - Summer 2026 (Avionics) jobs in United States
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Castelion · 9 hours ago

Flight Software Engineer Intern - Summer 2026 (Avionics)

positionTorrance, CA
timeInternship
remoteOnsite
seniorityIntern
money$30/hr - $30/hr
workcardStart in 2026 Summer

Castelion is bringing a new approach to defense development and production, focusing on short, iterative design cycles and rapid testing. The Flight Software Engineer Intern will help design, build, and test real-time embedded software for next-generation missile systems, collaborating with experienced engineers to ensure reliable operation under extreme conditions.

AerospaceGovernmentManufacturingMilitaryNational Security
badNo H1BnoteU.S. Citizen Onlynote
Hiring Manager
Julee Y.
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Responsibilities

Design, develop, and test real-time embedded flight software for missile systems
Collaborate with GNC engineers and hardware teams to integrate flight software with guidance, navigation, and control systems
Support simulation and hardware-in-the-loop (HIL) testing to validate performance
Debug and analyze software and hardware interfaces during bring-up and test campaigns
Participate in design reviews, code reviews, and configuration management
Document your work clearly and share learnings with the team to strengthen future designs

Qualification

C/C++ programmingReal-time operating systemsControl systems fundamentalsDebugging toolsSimulation environmentsFPGA-based systemsEmbedded software optimizationHigh commitmentClear communicationCreative problem solving

Required

Currently pursuing a BS or MS in Computer Engineering, Electrical Engineering, Computer Science, Aerospace Engineering, or a related technical field
Rising junior, senior, or graduate student at the time of the internship
Strong programming skills in C/C++ for embedded systems
Familiarity with real-time operating systems (RTOS) or bare-metal development
Understanding of control systems fundamentals and how they interact with flight software
Experience with debugging tools and working with hardware interfaces
U.S. Person status required (due to ITAR regulations)

Preferred

Familiarity with simulation environments and HIL test setups
Exposure to FPGA-based systems and embedded software optimization
Familiarity with missile systems, defense technology, or aerospace components
Strong interest in working in a fast-paced, high-ownership startup environment

Benefits

Compensation may vary based on experience and education level.
For non-local interns, housing or relocation stipends may be available to help offset temporary living expenses.

Company

Castelion

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Castelion is a defense tech company that applies modern hardware development and manufacturing processes to national security challenges.
dateFounded in 2022
location
Torrance, California, USA
people-size51-200 employees
web-link
https://www.castelion.com

Funding

Current Stage
Growth Stage
Total Funding
$469.61M
Key Investors
Lightspeed Venture PartnersSilicon Valley BankAndreessen Horowitz
2025-12-05Series B· $350M
2025-01-29Series A· $70M
2025-01-29Debt Financing· $30M

Leadership Team

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Bryon Hargis
Founder // CEO
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Andrew Kreitz
Co-Founder and CFO
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Recent News

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2025-12-09
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The Weekly Notable Startup Funding Report: 12/8/25
2025-12-09
Company data provided by crunchbase