Mechanical Assembly Lead at Castelion in Torrance, CA

Job description

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