Senior GNC Engineer

About the role

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 and technical excellence are decisive advantages - and we are building a team that can deliver real capability, not just concepts. This is a rare opportunity to join at an early stage, where your work will directly shape critical systems, influence major technical decisions, and have immediate, real-world impact.

Responsibilities

• Design and develop flight control and autopilot algorithms for high-speed flight vehicles across atmospheric and exo-atmospheric regimes
• Develop and implement advanced control strategies, including adaptive and robust control methods, to ensure performance under uncertain and dynamic conditions
• Conduct modeling, simulation, and analysis (3DOF/6DOF) to evaluate control system performance, stability, and robustness
• Work closely with avionics, flight sciences, mechanisms, and flight software teams to integrate control algorithms into real-time embedded systems
• Support hardware-in-the-loop (HIL) testing, flight testing, and post-flight analysis, translating results into system-level improvements
• Analyze vehicle dynamics, actuator behavior, and sensor characteristics to inform control system design and tuning
• Develop tools and frameworks for control system design, verification, and validation
• Mentor junior engineers and contribute to best practices in GNC and control system development
• Partner closely with program leadership to make technical trades aligned with mission success

Requirements

• Bachelor's, Master's, or PhD in Aerospace Engineering, Electrical Engineering, or related field
• 5+ years of experience in control system design, analysis, and validation for aerospace or high-performance dynamic systems
• Strong background in classical and modern control theory, including adaptive, nonlinear, and robust control methods
• Experience developing autopilot algorithms for missiles, rockets, hypersonic vehicles, or similar systems
• Proficiency in modeling and simulation tools such as MATLAB/Simulink or equivalent
• Experience with 3DOF and 6DOF simulation environments and real-time control implementation
• Familiarity with flight software integration and real-time embedded systems
• Strong problem-solving mindset, thriving in a fast-paced, hardware-rich, high flight cadence environment
• U.S. citizenship required; ability to obtain and maintain a U.S. government‑issued security clearance

Benefits

• Meaningful long-term equity for all full‑time employees
• Four (4) weeks of paid time off
• Ten (10) company‑paid holidays
• Comprehensive health benefits – 100% employee‑covered medical, strong dependent coverage, dental and vision plans
• Paid parental leave
• $100 monthly fitness stipend
• Onsite EV charging
• Catered meals, company‑covered food during high‑demand periods, fully stocked kitchen