About Castelion Castelion is redefining defense development through rapid iteration, aggressive testing, and modern commercial manufacturing at scale. We design, build, and test next-generation long-range strike weapon systems to give the United States and its Allies a decisive advantage and deter future conflicts. Avionics Hardware Engineer We are hiring Avionics Hardware Engineers to own flight‑critical electronics across design, bring‑up, test, and integration. This role is intended for engineers with experience in complex electronic systems who can take responsibility for avionics subsystems and operate effectively in a high‑tempo development environment. Engineers in this role may own areas such as motor controllers, avionics backplanes, power distribution, or outward‑facing avionics test and integration. Responsibilities • Own avionics hardware from architecture and schematic design through PCB layout, bring-up, and production support • Drive design decisions including component selection, interfaces, and system tradeoffs • Lead hardware bring-up, debugging, and root-cause analysis across lab, integration, and flight test • Collaborate cross-functionally to ensure avionics hardware meets performance, reliability, and mission requirements • Define and execute hardware validation strategies appropriate to development and flight maturity • Produce clear technical documentation covering designs, test results, and engineering changes • Partner with manufacturing and suppliers to transition hardware from prototype to production • Continuously improve designs based on test results, field data, and evolving requirements Basic Qualifications • Bachelor's degree in electrical engineering or related field • Proven end-to-end ownership of avionics or high‑reliability electronic hardware • Strong experience with PCB design, bring‑up, and lab debugging • Ability to operate autonomously and drive hardware issues to closure Preferred Qualifications • Avionics, aerospace, missile, space, automotive, or defense hardware experience • Experience with motor controllers, backplanes, power electronics, or flight hardware • Familiarity with MIL‑STD or aerospace hardware standards (e.g., DO‑254 exposure) • Embedded systems or FPGA‑adjacent hardware experience • Experience supporting hardware in integration, test, or flight environments Leadership Qualities • Bias to Action and Creative Problem Solving. Desire and experience questioning assumptions in ways that lead to break through ideas that are ultimately implemented. Successfully bring in applicable processes/concepts/materials from other industries to achieve efficiency gains. The ability to personally resolve minor issues in development without requiring significant support. • High Commitment, High Initiative. A successful candidate will have a genuine passion for Castelion's mission and consistently look for ways to contribute to the company's technical goals and prevent hardware blockers. Ability to work in a fast paced, autonomously driven, and demanding atmosphere. Strong sense of accountability and integrity. • Clear Communicator. Proactively communicates blockers. Trusted in previous roles to be voice of company with regulators, suppliers, gate keepers and customers. Capable of tactfully managing relationships with stakeholders to achieve company-desired outcomes without compromising relationships. Emails, IMs and verbal interactions are logical, drive clarity, and detailed enough to eliminate ambiguity. ITAR Requirements • To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State. 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. All employees are granted long-term stock incentives as part of their employment at Castelion. All employees receive access to comprehensive medical, vision, and dental insurance, and the company offers four weeks of paid time off per year.