Lead R&D Technician - 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.  

Mechanical Assembly Lead

Castelion is seeking a Mechanical Assembly Lead to perform hands-on assembly and integration activities for advanced aerospace and defense hardware. This is a full-time position located at our Torrance, CA facility. The Mechanical Assembly Lead will guide technicians and assemblers through complex mechanical builds, ensure work is performed safely and in accordance with drawings and procedures, and partner closely with engineering, manufacturing, quality, and operations to deliver hardware on schedule. This role is ideal for a hands-on leader who is comfortable working in a fast-paced research and development and production environment.

Responsibilities

• Lead daily mechanical assembly and integration activities, assigning work and coordinating priorities across the assembly team

• Train, mentor, and provide technical direction to assemblers and technicians while promoting a culture of ownership, safety, and quality

• Interpret and execute engineering drawings, models, bills of material, assembly instructions, travelers, and controlled procedures

• Perform and oversee precision mechanical assembly using hand tools, torque tools, power tools, fixtures, and fabrication equipment

• Coordinate with engineering to resolve build issues, provide manufacturability feedback, and implement design or process improvements

• Plan labor, tooling, materials, and work-cell readiness to maintain an efficient and predictable assembly workflow

• Verify dimensions, interfaces, torque values, fit, finish, and workmanship using appropriate inspection and metrology equipment

• Document build status, nonconformances, rework, test results, and completed work in accordance with quality-system requirements

• Support integration and functional testing of mechanical assemblies and ensure hardware is properly configured for downstream operations

• Maintain clean, organized, and appropriately controlled work areas, including cleanroom or contamination-controlled environments when required

• Drive continuous improvement in safety, quality, throughput, standard work, tooling, and assembly processes

Basic Qualifications

• 3+ years of hands-on experience in mechanical assembly, integration, manufacturing, or field

• 1+ years of experience leading, mentoring, or coordinating the work of an assembly or production team

• Ability to read and interpret engineering drawings, GD&T, CAD models, bills of material, work instructions, and technical documentation

• Proficiency with precision hand tools, torque tools, power tools, fixtures, and basic measurement and inspection equipment

• Strong understanding of mechanical interfaces, fasteners, torque application, alignment, sealing, and contamination control

• Ability to work effectively with engineering, quality, supply chain, and operations teams in a fast-paced environment

Preferred Skills and Experience

• Experience assembling flight hardware or other safety-critical, high-reliability systems

• Experience with cleanroom or controlled-environment assembly, ESD controls, FOD prevention, and contamination-control practices

• Experience with precision alignment, bonding, sealing, harness or tubing routing, or electromechanical integration

• Experience creating or improving standard work, assembly instructions, travelers, checklists, and tooling

• Experience using digital manufacturing, quality, inventory, or work-management systems

• Strong written and verbal communication skills, with the ability to clearly communicate status, risks, and technical issues

• Demonstrated judgment, attention to detail, and commitment to safe, right-first-time execution

• Ability to coach others, establish priorities, and make sound decisions in a changing, high-output environment

• Experience with lean manufacturing, root-cause analysis, or other continuous-improvement methods

• Ability to work from incomplete information and help mature processes from development through initial production

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 [email protected]. 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.