CNC Machinist

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 and technical excellence are decisive advantages - and we are building a team that can deliver real capability, not just concepts.

This is a rare opportunity to join at an early stage, where your work will directly shape critical systems, influence major technical decisions, and have immediate, real-world impact.

CNC Machinist – 5 Axis – 2nd Shift (230pm to 11pm)

As a CNC Machinist at Castelion, you will be responsible for machining & manufacturing complex components for high performance aerospace products.

Responsibilities

• Set up, operate, and program multi-axis CNC mills and lathes (up to 5-axis) to manufacture complex aerospace components
• Perform precision inspections using an array of metrology equipment to verify dimensions and ensure adherence to drawings and tolerances
• Read and interpret blueprints, CAD drawings, GD&T, and other technical documents to complete machining operations
• Manage cutting tools in CNC machines, ensuring optimal tool load and measurement for upcoming programs
• Troubleshoot and resolve operational issues, including alarm resolutions and tooling repairs, to maintain maximum machine uptime
• Operate CNC machines in a production environment, producing both development and flight hardware while meeting quick-turn program goals
• Conduct on-machine deburring and precision cleaning of components to ensure quality and reduce human intervention
• Maintain a clean and safe work environment, adhering to company guidelines and 5S principles
• Provide continuous feedback for process improvements and efficiency opportunities to engineering and leadership
• Actively participate in preventative maintenance of CNC machines on a weekly and monthly basis
• Communicate with shop leadership regarding production challenges and collaborate with teammates to support workflow

Basic Qualifications

• High school diploma or equivalency certificate
• 5+ years of experience in CNC machining, particularly with aerospace machine shops and hard metals
• Demonstrated proficiency in G-code, with strong setup and operational skills on CNC mills and lathes
• Ability to read and understand complex blueprints, GD&T, and tolerances

Preferred Skills and Experience

• Experience with various materials such as Inconel, titanium, stainless steel, copper, and aluminum
• 3+ years of setup experience on vertical mills
• 1+ year of experience setting up and operating 5-axis mills
• Familiarity with CNC programming using software such as NX, Solidworks HSM, Mastercam, Fusion 360 or Esprit CAD/CAM
• Experience with multiple CNC control systems, including Heidenhain, Haas, Fanuc, Siemens, and others
• Strong mechanical aptitude and understanding of tooling technology and shop math
• Excellent interpersonal skills and the ability to contribute to a team-oriented environment.

Benefits And Perks

• Employee Equity: Meaningful equity for all full-time employees - share value has increased 150x in three years
• Personal Time Off: Four (4) weeks of paid time off to unplug, reset, and come back sharp—velocity matters, burnout doesn't
• Company Paid Holidays: Ten (10) company paid holidays
• Medical: We offer plans at 100% employee covered and 80% of dependent coverage
• Dental & Vision: We cover 90% employees and 80% for dependents to ensure you and your family have access to quality preventive and ongoing care
• FSA/HSA: To support long-term health and financial resilience, we offer FSA and HSA options that allow employees to set aside pre-tax dollars for eligible medical and dependent care expenses
• Retirement: 401k plan offered to support long term financial growth along side high-impact, high-velocity work
• Paid Parental Leave: We support growing families with meaningful time to bond and recover. Birthing parents are eligible for up to 10 weeks of paid leave, while non-birthing parents may take up to 4 weeks of paid leave. This time can be used for pre-natal care, pregnancy, childbirth, and related medical needs—ensuring every parent has the support they need during this important life moment.8-weeks of paid parental leave for all parents. Additional paid pregnancy leave for CA employees
• Meals & Catering: Frequently