Senior Buyer, CNC Machined Parts & Assemblies 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. 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, qualit