Lead Flight Software Engineer

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. Lead Flight Software Engineer As a Lead Flight Software Engineer, you will serve as a key technical leader within Castelion's Flight Software organization. You will work closely with the Head of Flight Software to define architecture, guide engineering direction, and ensure reliable delivery of mission-critical embedded software across the vehicle stack. In addition to owning complex subsystems, you will mentor engineers, coordinate cross-functional efforts, and set the technical tempo for the team. This role is ideal for engineers who combine deep technical expertise with an ability to lead others, influence system-level decisions, and thrive in a fast-moving, highly integrated hardware - software environment. Responsibilities • Architecture & Technical Leadership: Partner with the Head of Flight Software to define system architecture, software design patterns, module interfaces, and long-term technical strategy. Provide technical leadership across embedded systems, autonomy, drivers, simulation, and application layers, and lead deep-dive investigations into software reliability, performance, and integration issues. • Embedded Software Development: Design, implement, and integrate embedded software for Linux-based and real-time systems. Own high-impact subsystems from concept through flight testing. Perform hands-on debugging, hardware bring-up, and system validation across tightly coupled hardware–software interfaces. • Team Leadership & Mentorship: Serve as day-to-day technical lead for the embedded software team by mentoring engineers, reviewing designs and code, and providing guidance on implementation approaches. Break down complex projects into clear milestones, track progress, and ensure high-quality execution across the team. Responsible for the career growth of other team members. • Cross-Functional Collaboration: Work closely with avionics, guidance, hardware, simulation, and test teams to align software efforts with broader system requirements. Represent the embedded software team in program reviews, technical discussions, and mission-planning activities. • System Integration & Testing: Lead software integration across virtualized environments, hardware-in-the-loop, and full vehicle setups. Develop or guide the development of testing tools, automation workflows, and simulation models. Drive root-cause analysis for complex failures and implement system-level corrective actions. • Project Ownership & Delivery: Own major technical initiatives that impact vehicle capability, autonomy, performance, or reliability. Coordinate resources, manage risks, and ensure on-time delivery of mission-critical software. Support integration and launch activities at test sites when necessary. • Quality, Standards & Continuous Improvement: Elevate engineering standards by driving improvements to code quality, design review processes, documentation expectations, and testing rigor. Foster a culture of high ownership, rapid iteration, and continuous improvement across the software organization. Basic Qualifications • Bachelor's degree in computer science, computer engineering, electrical engineering, math, or a related STEM field. • 7+ years of professional experience in embedded software or real-time systems. • Strong proficiency in C++, Rust, or similar systems programming languages. • Experience developing software on Linux-based embedded platforms, including kernel-level work or custom driver development (UART, I2C, SPI, etc.). • Experience leading technical projects, architecting complex systems, or serving as a team or technical lead. • Strong debugging skills across hardware/software boundaries. Preferred Skills and Experience • Technical leadership experience at high-performance or mission-critical hardware–software organizations (defense, aerospace, robotics, automotive, etc.). • Hands-on experience with real-time systems, microcontrollers (ARM, PowerPC, x86), and distributed embedded architectures. • Strong Linux internals knowledge, including performance tuning, networking, and system-level diagnostics. • Proven ability to mentor engineers and provide feedback, elevate engineering standards, and run design reviews. • Experience aligning multidisciplinary teams and influencing system-wide decisions. • Demonstrated ability to rapidly prototype, evaluate tradeoffs, and validate ideas using first-principles thinking. 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 hr@castelion.com. 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.