Mission Integration Engineer

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 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.

Mission Integration Engineer

As a Mission Integration Engineer, you will be the primary technical liaison between Castelion and our government customers, supporting the integration of advanced weapons systems into operational environments. You will drive the entire lifecycle of weapons programs, from early capability studies through prototype development, test, and operational deployment.

This role requires a combination of deep technical expertise, strong program execution skills, and the ability to engage directly with government stakeholders. You will work closely with internal teams across engineering disciplines including propulsion, avionics, guidance/navigation/control (GNC), software, flight test, and manufacturing to ensure mission success.

Responsibilities

• Serve as a customer interface, ensuring alignment between government mission requirements and Castelions weapon system designs.
• Support all phases of the program from concept development and initial proposals through successful test, flight, and deployment.
• Lead mission planning and test efforts, ensuring end-to-end system integration and operational readiness.
• Work across internal teams to develop and execute prototype development strategies, ensuring timely delivery of cutting-edge weapons solutions.
• Collaborate with engineers and leads to optimize weapons system performance through design trades and cross-discipline coordination.
• Represent Castelion at customer meetings, design reviews, test campaigns, and technical demonstrations.
• Ensure contract deliverables are met on time and to customer specifications.
• Provide technical leadership in weapons system verification and test planning, ensuring robust validation and mission success.
• Support live-fire and flight test operations, including pre-test analysis, real-time mission support, and post-test evaluation.
• Maintain an in-depth understanding of government acquisition processes, certification requirements, and compliance standards.

Basic Qualifications

• Strong passion for advancing national security and a deep commitment to developing cutting-edge defense technologies to support the warfighter.
• Bachelor's degree in aerospace engineering, mechanical engineering, electrical engineering, physics, or a related technical field.
• 2+ years of experience in systems engineering, mission integration, or related roles within the defense or aerospace industry.
• 2+ years of experience in technical project management and/or weapons system development.
• Experience working with DoD or other national security agencies.
• Hands-on experience with launch vehicles, weapons systems, or other aerospace defense platforms.
• Strong ability to analyze and synthesize complex technical information and communicate effectively with both engineers and external stakeholders.
• Ability to obtain and maintain a Top Secret/SCI security clearance

Preferred Qualifications

• Masters degree in a relevant technical field.
• Experience with hypersonic weapons, missile defense, or advanced guidance systems.
• Strong background in spacecraft or missile mission design, development, integration, and/or test.
• Ability to work under pressure and manage multiple parallel priorities effectively.
• Highly detail-oriented with strong analytical, verbal, and written communication skills.
• Active Top Secret/SCI security clearance preferred.

Additional Requirements

• Ability to travel up to 25% of the time for customer meetings, test campaigns, and program execution.

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.

Benefits And Perks

All full-time employees are granted meaningful long-term equity, sharing in the company's significant growth trajectory. We offer four (4) weeks of paid time off, ten (10) company-paid holidays, and comprehensive health benefits - including 100% employee-covered medical and strong dependent coverage, along with dental and vision plans. We also provide paid parental leave to support growing families, a $100 monthly fitness stipend to promote health and performance, and onsite EV charging for convenience. In addition, employees enjoy perks like catered meals, company-covered food during high-demand periods, and a fully stocked kitchen to stay fueled throughout the day.

Affirmative Action/EEO Statement

Employment with Castelion is governed on the basis of competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.