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. Avionics Harness Design Engineer We are seeking an Avionics Harness Design Engineer to lead the design, development, and integration of electrical harnessing across our missile and vehicle systems. This engineer will play a critical role in ensuring robust, manufacturable, and high-reliability electrical connectivity throughout the system. You will partner closely with avionics, power, structures, and propulsion teams to deliver mission-critical hardware in a fast-paced, hardware-rich environment. You will additionally support avionics and harness integration at the system and vehicle levels. Responsibilities • Design, route, and document electrical harnesses to support missile and vehicle system integration • Generate wiring diagrams, schematics, and harness assembly drawings in accordance with aerospace standards • Select appropriate wires, connectors, backshells, shielding, and protection materials to meet environmental and system requirements • Collaborate with avionics, power, and structural engineering teams to ensure proper integration of harnesses into overall vehicle design • Develop and maintain harness BOMs (bill of materials) and ensure manufacturability at scale • Support harness build, installation, and troubleshooting during integration and testing • Ensure designs meet electrical, mechanical, and thermal requirements for high-reliability aerospace applications • Identify and implement process improvements to increase efficiency, manufacturability, and quality Basic Qualifications • Bachelor's or Master's degree in Electrical Engineering, Mechanical Engineering, Aerospace Engineering, or related field • 2+ years of experience in cable harness design for aerospace, defense, or high-reliability hardware systems • Proficiency with CAD/ECAD tools for harness design (e.g., CATIA, Creo, SolidWorks Electrical, Capital, RapidHarness, AutoCAD, or equivalent) • Strong knowledge of aerospace wiring standards (e.g., IPC/WHMA-A-620, NASA-STD-8739, or MIL-SPEC requirements) • Familiarity with harnessing in environments with high thermal and small volume requirements • Hands-on experience supporting harness manufacturing, assembly, and testing • Ability to work cross-functionally with avionics, power, propulsion, and integration teams • Strong problem-solving and troubleshooting skills in test and integration environments 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. While this position does not currently require a U.S government-issued security clearance, it may in the near future. Therefore, the ability to obtain and maintain a U.S. government–issued security clearance is required. U.S. citizenship is required, as only U.S. citizens are eligible for a security clearance. 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.