Manufacturing Engineer, Mechanical Assembly

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. Manufacturing Engineer, Mechanical Assembly Castelion is seeking a highly skilled Manufacturing Engineer to develop, validate, and stand up the processes and tooling that turn mechanical assembly designs — actuators, mechanisms, bonded assembles, structural sub-assemblies — into repeatable, high-rate production. You will spend as much time on the floor as at your desk: designing fixtures, releasing work instructions, training operators, and driving process validation from first article through full-rate production. The ideal candidate is comfortable owning a process end-to-end, from concept through PFMEA, qualification, and hands-on troubleshooting on the line. Responsibilities • Develop, validate, and release manufacturing processes, work instructions, and process specifications for mechanical assembly operations • Design, procure, and qualify production tooling, fixtures, and manufacturing aids required for in-house production • Lead process validation activities — first article inspections, process capability studies, and PFMEA — to qualify new processes for production • Train and certify operators on new and revised processes, owning the process side of workforce ramp-up • Establish process controls, manufacturing standards, and inspection requirements to ensure consistent product quality • Partner with design engineering to provide DFM feedback and resolve build issues surfaced during production • Own real-time troubleshooting on the assembly floor, driving containment and root-cause corrective action for quality, yield, and throughput issues • Support the transition of processes from engineering development builds into documented, repeatable production, including workstation design and line layout • Work cross-functionally with design, quality, supply chain, procurement, and program management to meet performance, schedule, and cost objectives Basic Qualifications • Bachelor's degree in mechanical engineering, manufacturing engineering, or aerospace engineering • 3+ years of experience developing or validating manufacturing processes in a production, manufacturing, or experimental environment Preferred Skills and Experience • Hands-on tooling and fixture design experience, from concept through fabrication and qualification • Experience generating high-quality work instructions within an MES • Experience with NX/Teamcenter CAD/PDM • Strong understanding of the APQP framework, specifically Control Plans, DFMEA, PFMEA, and managing Significant/Critical Characteristics • Previous involvement in a high-speed or high-output production environment, with hands-on experience on a production line • Experience with automation, robotics, and flexible manufacturing systems • Experience with electro-mechanical mechanisms or complex mechanical assemblies • Comfortable using hand tools, power tools, and fabrication equipment • Familiarity with surface preparation and bonding operations with RTVs and Epoxies • Familiarity with Atlassian tools such as Confluence and JIRA • Excellent communication skills, both written and oral, along with effective teamwork abilities • Ability to acclimate to frequently changing assignments and a fast-paced working environment 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. 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. Government requirements. If the position is so designated, your employment in the role may be contingent upon your ability to obtain and maintain the required U.S. Government security clearance or other government authorization, and to satisfy any citizenship or other eligibility requirements imposed by applicable law, regulation, executive order, or government contract requirements. You will be notified if and when such requirements apply. Affirmative Action/EEO Statement Castelion is an Equal Opportunity Employer. We are committed to providing equal employment opportunities to all applicants and employees without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability, genetic information, protected veteran status, or any other characteristic protected by applicable federal, state, or local law. Castelion is committed to providing reasonable accommodations to qualified individuals with disabilities throughout the application and hiring process. If you require a reasonable accommodation to complete an application, participate in the interview process, or otherwise participate in the hiring process, please contact hr@castelion.com. Requests for accommodation will be considered on an individual basis and handled in accordance with applicable law. Castelion is committed to fostering a workplace where employment decisions are based on qualifications, business needs, and the ability to perform the essential functions of the role, with or without reasonable accommodation. EAR/ITAR Requirements This position requires access to export-controlled information, and as such, employment (or hiring of a contractor) is contingent upon the candidate’s ability to access all applicable export-controlled information without additional export licensing being required by the Bureau of Industry and Security and/or the Directorate of Defense Trade Controls