Development Test Engineer

The Development Test Engineer owns the planning, execution, and analysis of tests that turn designs into flight-ready hardware. 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 hardware, write procedures, run tests, break things early, and close the loop back into design with clear data and recommendations.

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

• Own development and qualification testing for avionics, mechanisms, propulsion, structures, and integrated vehicle subsystems
• Design and build test fixtures, ground support equipment (GSE), and instrumentation for benchtop, environmental, and system-level tests
• Author test plans, procedures, and reports aligned with program requirements and qualification intent
• Execute vibration, thermal, shock, EMI/EMC, functional, and performance testing
• Instrument hardware and vehicles with sensors (strain, temp, pressure, accel, current/voltage) and DAQ systems
• Lead anomaly detection, root-cause analysis, and corrective action closure
• Partner closely with design engineering to feed test results back into rapid design iteration
• Support integration operations, range testing, and flight test campaigns as needed
• Maintain rigorous configuration control, data management, and test documentation
• Improve test infrastructure, automation, and data quality to increase test cadence and learning velocity

Test Plan/Schedule, Test Plan/Schedule, Testing, Procedure Development, Test Design, Requirements Management, Manufacturing Operations, Analysis Skills, System Test, Hardware Quality Assurance, * Bachelors degree in Mechanical, Electrical, Aerospace, or related engineering field

• 3+ years of hands-on development and test experience (academic, industry, or both)
• Experience planning and executing hardware tests from concept through report-out
• Proficiency with test instrumentation and lab equipment (DAQs, oscilloscopes, power supplies, sensors)
• Ability to design and fabricate simple test fixtures and GSE (CAD + shop familiarity)
• 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
• Operates with high ownership, bias to action, attention to detail, and a test-driven engineering mindset
• Comfortable working in fast-moving environments where hardware is the source of truth

Preferred Skills and Experience

• Aerospace, missile, launch vehicle, space, or defense hardware testing
• Environmental testing: vibration, thermal-vacuum, thermal cycling, shock
• Test automation and data analysis using Python, MATLAB, or similar
• 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

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.