Senior Buyer, CNC Machined Parts & Assemblies

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.

Senior Buyer, CNC Machined Parts & Assemblies

As a Senior Buyer on Castelion’s Strategic Sourcing team, focused on CNC machined parts and assemblies, you will be responsible for sourcing and procuring complex metallic and non-metallic components in a fast-paced aerospace and defense environment. You will partner closely with engineering, manufacturing, quality, planning, and finance to secure capable suppliers, execute competitive commercial strategies, and ensure material is available to support rapid development, qualification, testing, and production.

The ideal candidate brings strong practical knowledge of CNC machining, including machined metal and non-metal materials, tolerancing, inspection, finishing, and assembly processes. This role requires an experienced supply chain professional who can move quickly, exercise sound judgment, resolve supplier issues, and build a resilient, cost-effective supply base while maintaining rigorous quality, schedule, compliance, and configuration-control standards

Responsibilities

Source, qualify, and manage suppliers for CNC machined parts, machined assemblies, and related manufacturing processes across metallic and non-metallic materials, including aluminum, steel, stainless steel, titanium, nickel-based alloys, plastics, composites, and other engineered materials as applicable.

Partner with engineering and manufacturing to translate drawings, models, specifications, GD&T, special-process requirements, inspection requirements, and assembly needs into executable sourcing and purchase strategies.

Develop and execute supplier strategies that balance quality, technical capability, capacity, lead time, total cost, schedule risk, geographic considerations, and long-term scalability.

Lead RFQs and competitive bidding events; analyze supplier quotes, should-cost drivers, tooling and NRE, setup charges, material assumptions, outside processing, freight, payment terms, and escalation provisions.

Negotiate pricing, lead times, capacity commitments, terms and conditions, quality requirements, warranties, tooling ownership, intellectual property protections, and other commercial terms in purchase orders, MSAs, LTAs, and related agreements.

Own purchase order execution and supplier follow-through for assigned parts and assemblies, including demand signals, acknowledgments, delivery dates, expedite actions, changes, shortages, and recovery plans.

Facilitate design-for-manufacturability and design-for-supply-chain reviews early in NPI to identify machining risks, tolerance challenges, alternate materials, alternate processes, second sources, standardization opportunities, and cost-reduction options before design freeze.

Work with Supplier Quality Engineering and suppliers to resolve nonconformances, improve first-pass yield, implement corrective actions, and prevent recurrence of rejected or late material.

Assess supplier manufacturing capacity and process capability, including CNC equipment, fixturing, programming, inspection, surface treatment, heat treatment, non-destructive testing, special processes, and assembly capability.

Coordinate with planning and operations to maintain accurate MRP/ERP data, bills of material, supplier records, purchase orders, lead times, minimum order quantities, and other master data required for material availability.

Monitor supplier performance and provide clear updates on critical supply issues, recovery plans, cost, quality, and schedule to program and functional leadership.

Identify and mitigate supply-chain risks through dual sourcing, capacity reservations, buffer strategies, supplier development, business continuity planning, and early escalation of constraints.

Ensure sourcing and procurement activities comply with company policies, contractual requirements, ITAR/EAR and other export-control obligations, applicable government regulations, quality standards, and customer requirements.

Build trusted relationships with suppliers and internal stakeholders; travel periodically to supplier and company locations, including Torrance, CA and Allen, TX, as business needs require.

Performance Expectations

On-time delivery: Maintain assigned supplier on-time delivery at or above program targets, with timely recovery plans for any misses.

Quality: Improve and sustain supplier first-pass acceptance and reduce recurring nonconformances, escapes, and corrective-action aging.

Cost and value: Deliver measurable cost savings, cost avoidance, and should-cost improvements while protecting technical and schedule requirements.

Supplier readiness: Establish qualified capacity and executable sourcing plans for new and existing CNC machined parts before required dates.

Execution: Maintain accurate ERP/MRP and purchase-order data, provide timely acknowledgments, and close expedites and action items with urgency.

Risk management: Identify high-risk suppliers, parts, processes, and capacity constraints early and implement documented mitigation plans.

Stakeholder effectiveness: Provide concise, accurate status and escalate issues with clear options, impacts,

Basic Qualifications

Bachelor’s degree or equivalent experience in supply chain, business, engineering, manufacturing, operations, or a related discipline.

5+ years of experience in purchasing, strategic sourcing, supply chain, supplier management, or a related role in aerospace, defense, space, automotive, or another complex manufacturing environment.

Demonstrated experience sourcing CNC machined parts and/or assemblies, including both metallic and non-metallic materials.

Experience interpreting engineering drawings, specifications, GD&T, bills of material, and manufacturing or inspection requirements.

Experience with RFQs, supplier negotiations, purchase orders, supplier performance management, and cross-functional problem solving.

Ability to work effectively in a fast-paced environment with shifting priorities, incomplete information, and aggressive development and production schedules.

Active U.S. Government security clearance or the ability to obtain one, as required by the role.

Preferred Skills and Experience

Proficiency and hands-on experience with CNC machining processes for metallic and non-metallic parts, including milling, turning, multi-axis machining, fixturing, programming, and process planning.

Knowledge of material specifications and manufacturing processes such as heat treatment, anodize, plating, passivation, coating, chemical processing, NDT, and other special processes.

Experience with complex machined assemblies, tight-tolerance components, low-to-medium volume production, prototype/NPI builds, flight hardware, or high-reliability aerospace products.

Understanding of inspection methods and quality systems, including CMM, first article inspection, AS9100, ISO 9001, AS9102, source inspection, and root-cause/corrective-action methods.

Experience managing tooling, fixtures, gauges, supplier-owned or customer-owned assets, and non-recurring engineering costs.

Experience with MRP/ERP systems and ownership of bills of material, work orders, purchase orders, supplier master data, and lead-time information.

Experience negotiating MSAs, LTAs, capacity agreements, buffer stock, VMI, and other supply continuity arrangements.

APICS, CPSM, Six Sigma, or similar certification; strong analytical skills using Excel, SQL, or advanced analytics tools.

Experience with ITAR/EAR-controlled hardware, defense procurement, government contracting requirements, or related compliance obligations.

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.