Development Test Engineer - Mechanisms at Castelion in Torrance, CA

Job description

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. Development Test Engineer - Mechanisms The Development Test Engineer owns the planning, execution, and analysis of tests that turn designs into flight-ready mechanisms. This role sits at the center of engineering, manufacturing, and operations—translating requirements into real-world validation through benchtop, environmental, subsystem, and vehicle-level testing. You will design test stands and write automation software to enable rapid testing to drive iterative design. This is a hands-on role for engineers who thrive in fast-paced, ambiguity-heavy environments and believe the fastest way to learn is to test real hardware. Responsibilities Translate system and subsystem requirements into test objectives, acceptance criteria, and verification methods Own development and acceptance testing for flight mechanisms for Castelion’s hypersonic strike missiles Design and build complex test stands with integrated load actuators and instrumentation Develop automated test software for instrument control, test sequencing, data logging, and analysis; Python is preferred. Maintain rigorous configuration control, data management, and test documentation Improve test infrastructure, automation, and data quality to increase test cadence and learning velocity Support flight tests and rocket motor static fires as required Basic Qualifications Bachelor’s degree in Mechanical, Electrical, Aerospace, or related engineering field 3+ years of experience developing, integrating, or testing mechanical, electromechanical hardware Proficiency with test instrumentation and lab equipment (DAQs, oscilloscopes, power supplies, sensors) Knowledge of common sensors like load cells, pressure transducers, LVDTs, encoders Strong debugging, troubleshooting, and root-cause analysis skills Comfortable working across disciplines in high-ownership environments Willingness to support extended hours, weekends, travel, and on-site operations during critical test campaigns Comfortable working in fast-moving environments where hardware is the source of truth Preferred Skills and Experience Aerospace, automotive, defense or other high-reliability hardware testing Environmental testing: vibration, thermal-vacuum, thermal cycling, shock Flight test, range operations, or hardware-in-the-loop (HIL) experience Familiarity with requirements verification, qualification evidence, and failure tracking Hands-on machining, wiring, soldering, or rapid prototyping experience What We Value Hands-on rigor: deep understanding of systems through direct testing and failure analysis. Autonomy and ownership: you don't wait for direction you seek out what needs to be tested and make it happen. High standards for reliability, data quality, and test repeatability. Systems-level thinking: understanding how actuator behavior affects broader vehicle performance. 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. Gove