Mechanical Design Engineer Trainee Jobs in California

Hadrian is building autonomous factories that help aerospace and defense companies manufacture rockets, satellites, jets, and ships up to 10x faster and up to 2x cheaper. By combining advanced software, robotics, and full‑stack manufacturing, we are reinventing how America produces its most critical parts.

We’re accelerating our mission with the launch of Factory 3 in Mesa, Arizona, a 290,000‑square‑foot facility creating 350 new jobs. We are expanding rapidly to support thousands of future hires, launching Hadrian Maritime to expand into naval production, and introducing a Factory-as-a-Service model that delivers complete systems instead of individual parts.

Hadrian is backed by leading investors including T. Rowe Price, Lux Capital, Founders Fund, and Andreessen Horowitz, our fast-growing team is united around reindustrializing American manufacturing for the 21st century and beyond.

We are seeking a Mechanical Design Engineer to support the development of custom industrial machinery, automation equipment, robotic tooling, and mechanical systems. This role owns mechanical design activities from concept through manufacturing, assembly, testing, and commissioning. The ideal candidate combines strong CAD expertise with hands‑on knowledge of fabrication, manufacturing, and automated equipment, while collaborating across engineering and operations teams to deliver reliable, scalable solutions.

• Design mechanical systems, machine assemblies, fixtures, tooling, and robotic end‑of‑arm tooling (EOAT) using 3D CAD software.

• Create manufacturing drawings, bills of materials, and engineering documentation while applying GD&T and design‑for‑manufacturing principles.

• Support fabrication, machining, welding, assembly, prototype builds, and testing activities to ensure successful execution of designs.

• Collaborate with manufacturing, controls, project management, suppliers, and technicians to develop and improve equipment and processes.

• Support design reviews, troubleshooting, startup, commissioning, and continuous improvement efforts to optimize performance, reliability, and cost.

• Bachelor’s degree in Mechanical Engineering or a related engineering discipline.

• 2+ years of mechanical design experience in industrial, manufacturing, automation, or related environments.

• Proficiency with SolidWorks or similar 3D parametric CAD software.

• Understanding of machining, welding, fabrication, assembly processes, engineering drawings, and GD&T.

• Strong problem‑solving, organizational, and communication skills with the ability to work effectively in cross‑functional teams.

• Experience designing custom machinery, automation equipment, robotics, fixtures, tooling, or EOAT systems.

• Experience with pneumatic, hydraulic, vacuum, motion control, or sensor‑integrated mechanical systems.

• Hands‑on experience supporting prototype builds, equipment assembly, testing, and commissioning.

• Familiarity with FEA, engineering analysis tools, or mechanical simulation methods.

• Experience working in manufacturing, startup, or fast‑paced engineering environments.

• 100% coverage of medical, dental, vision, and life insurance plans for employees.

• 401k.

• Relocation stipend or support as appropriate.

• Flexible vacation policy.

• Equity.

To conform to U.S. Government space technology export regulations, including the International Traffic in Arms Regulations (ITAR) you must be a U.S. citizen, lawful permanent resident of the U.S., protected individual as defined by 8 U.S.C. 1324b(a)(3), or eligible to obtain the required authorizations from the U.S. Department of State. Learn more about the ITAR here.

It is the Company’s policy to provide equal employment opportunity for all applicants and employees. The Company does not unlawfully discriminate on the basis of race inclusive of traits historically associated with race (including, but not limited to, hair texture and protective hairstyles, such as braids, locks and twists), color, religion, sex (including pregnancy, childbirth, or related medical conditions), gender identity, gender expression, transgender status, national origin (including, in California, possession of a drivers license), ancestry, citizenship, age, physical or mental disability, height or weight, medical condition, family care status, military or veteran status, marital status, domestic partner status, sexual orientation, genetic information, exercise of reproductive rights, any other basis protected by local, state, or federal laws, or any combination of the above characteristics. When necessary, the Company also makes reasonable accommodations for disabled candidates and employees, including for candidates or employees who are disabled by pregnancy, childbirth, or related medical conditions.