CHAOS Industries is redefining modern defense with a multi-product portfolio that gives the ultimate advantage—domain dominance. The company's products are powered by Coherent Distributed Networks (CDN™), empowering warfighters, commercial air operators, and border protection teams to act faster, adapt rapidly, and stay ahead of evolving threats.  CHAOS Industries was founded in 2022 and has raised a total of $1 billion in funding from leading investors, including 8VC, Accel, and Valor Equity Partners. The company is headquartered in Los Angeles, with offices in Washington, D.C., San Francisco, San Diego, Seattle, and London. For more information, please visit www.chaosinc.com. Role Overview:  CHAOS is seeking a Principal Hardware-in-the-Loop (HIL) Engineer to lead the architecture, development, and deployment of advanced HIL simulation environments supporting high-reliability effector platforms. This role is responsible for defining scalable, high-fidelity validation frameworks that enable full system integration testing across multiple programs—bridging software, autonomy, and flight hardware.  This position spans the full lifecycle of HIL development, from early requirements shaping and simulation architecture through hardware/software integration, automated test development, system validation, and transition to flight test. The ideal candidate is a highly experienced, hands-on engineer who can lead complex HIL efforts, guide other engineers, and ensure consistent, high-quality validation approaches across programs.  This is a full-time, on-site position in El Segundo, CA.    Responsibilities:  * Lead the architecture, design, and development of HIL test benches for full effector system integration, including flight controllers, ESCs, sensors, and ground control systems  * Define HIL strategy, fidelity requirements, and validation approaches to ensure comprehensive system-level test coverage prior to flight  * Establish reusable approaches for HIL system design, model integration, and test automation across programs  * Architect and integrate high-fidelity simulation models (flight dynamics, actuator, and sensor models) that accurately replicate real-world behavior  * Lead integration of hardware components into HIL systems, including flight computers, ESCs, communication links, sensors, and power systems  * Drive development of automated test frameworks, regression infrastructure, and CI/CD integration for continuous validation of software and firmware  * Guide debugging and root cause analysis of complex hardware-software interactions using HIL data, logs, and telemetry   * Collaborate with GNC, software, and systems engineering teams to define verification strategies, test plans, and acceptance criteria across programs  * Own, maintain, and improve test infrastructure, including simulation software, real-time targets, and data acquisition systems  * Document test methodologies, procedures, and results clearly for cross-functional team use  * Support transition of HIL-validated systems to integration and flight test phases    Minimum Requirements:  * Bachelor's degree in Engineering, Computer Science, or a related field  * 10+ years of experience in hardware-in-the-loop testing, embedded systems integration, or a closely related discipline  * Hands-on experience building and operating HIL or SIL simulation environments for embedded or autonomous systems  * Proficiency in real-time simulation platforms (e.g., dSPACE, NI VeriStand, or similar)  * Strong programming skills in Python and/or C/C++ for test automation and system scripting  * Familiarity with flight controller software such as PX4, ArduPilot, or equivalent  * Experience with communication protocols common in drone systems (MAVLink, CAN, UART, SPI, I2C)  * Solid understanding of effector system architecture, including propulsion, navigation, and control loops  * Experience with version control systems and CI/CD pipelines for automated testing  * Strong analytical, debugging and root cause analysis skills across hardware, software, and simulation domains  * Demonstrated ability to lead technical efforts and guide engineers through complex integration and troubleshooting challenges  * Ability to obtain and maintain a U.S. security clearance    Preferred Requirements:  * Advanced degree (MS or PhD) in Engineering or related field  * Experience with ROS or ROS 2 for simulation and integration testing  * Strong background in flight dynamics, control systems, or GNC model development (MATLAB/Simulink or similar)  * Experience correlating simulation environments with real-world flight test data  * Familiarity with FPGA-based simulation, embedded Linux systems, or real-time computing architectures  * Experience with RF systems, GPS signal simulation, or sensor fusion validation  * Experience establishing reusable simulation frameworks or model libraries across programs  * Exposure to flight test operations and transitioning systems from HIL to field testing  * FAA Part 107 certification or equivalent UAV operational credentials  Why CHAOS? * Health Benefits: Medical, dental, and vision benefits 100% paid for by the company * Additional benefits: 401k (+ 50% company match up to 6% of pay), FSA, HSA, life insurance, and more * Our Perks: Free daily lunch, ‘No meeting Fridays’, unlimited PTO, casual dress code * Compensation Components: Competitive base salaries, generous pre-IPO stock option grants, relocation assistance, and (coming soon!) annual bonuses * Team Growth: 250 employees and counting across 5 global offices $170k-240k The stated compensation range reflects only the targeted base compensation range and excludes additional earnings such as bonus, equity, and benefits. If your compensation requirements fall outside of the range, we still encourage you to apply. The salary range for this role is an estimate based on a range of compensation factors, inclusive of base salary only. Actual salary offer may vary based on (but not limited to) work experience, education and/or training, critical skills, and/or business considerations.    ---------------------------------------- RECRUITING AGENCIES: CHAOS INDUSTRIES DOES NOT ACCEPT UNSOLICITED RESUMES OR OUTREACH. UNSOLICITED SUBMISSIONS WILL NOT BE REVIEWED OR COMPENSATED. ----------------------------------------   #LI-onsite