Principal Mechanical Engineer

About the role

Join the power movement as a Principal Mechanical Engineer at Commonwealth Fusion Systems (CFS). CFS is on a mission to deliver the urgent transition to fusion energy, combining decades of research, top talent, and new technologies to build commercially viable fusion power plants. We're working with policymakers and suppliers to build the energy industry of the future.

Responsibilities

• Lead System Design: Drive the design, integration, and validation of advanced R&D equipment for thin-film processing
• Define Requirements: Establish system-level requirements and innovative design concepts that directly correlate mechanical precision to final thin-film product quality
• Standardize Best Practices: Implement and maintain engineering workflows, and best practices using semiconductor standards as your guide
• Lead Design Reviews: Conduct rigorous reviews for overall mechanical systems and sub-systems, emphasizing manufacturability (DFx) and best practices for mechanical design
• Collaborate & Interface: Generate and maintain critical interfaces with cross-functional teams, including scientists, vacuum specialists, and electrical engineers
• Project Accountability: Report on project milestones to stakeholders, ensuring delivery of on-time and in-spec outcomes
• Mentor Talent: Coach engineering staff on technical delivery, procedural discipline, and professional development
• Get Things Done: Act with speed to drive projects from concept through assembly, testing, and implementation

Requirements

• Education: Master’s degree in Mechanical Engineering or a related field (or equivalent industrial experience)
• Experience: 15+ years of experience in the design and implementation of complex R&D systems or semiconductor manufacturing equipment
• Thermal & Structural Expertise: Proven capability in high-temperature structural design and complex thermal management within vacuum environments
• Vacuum System Proficiency: Deep understanding of vacuum architecture, including material outgassing, seal integrity, and pump-down optimization
• Software Mastery: Expertise in 3D modeling (SolidWorks and/or NX) and FEA/Thermal simulation tools (COMSOL, ANSYS)
• Hands-on Capability: Ability to bridge the gap between design and the shop floor, including experience with manual/CNC machining, prototyping, and hardware troubleshooting
• Vendor Management: Experience selecting and qualifying global vendors for specialized components or custom sub-systems
• Leadership: Demonstrated ability to lead effectively in both direct and matrixed organizational structures
• Bonus Points For: R2R Expertise: Experience designing or integrating roll-to-roll (R2R) systems for material processing, Semiconductor Background: Prior success building first-of-kind or experimental tools for semiconductor R&D or thin-film deposition, Standards Knowledge: Familiarity with SEMI, ASME, ASTM, and other industry-standard mechanical codes, Motion Control: Experience designing precision motion and motor-controlled systems within challenging environments

Qualifications

• Must-have Requirements: Ability to occasionally lift up to 50 lbs, Perform activities such as stooping, climbing, standing, or sitting for extended periods of time, Dedication to safety to mitigate industrial hazards that may include heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, and cryogenics, Willingness to travel or work required nights/weekends/on-call occasionally

Benefits

• $150,000 - $225,000 a year Salary range for this full-time position + equity + benefits
• Competitive compensation with equity
• 13 Company-wide Holidays
• Flexible vacation days
• 10 sick days
• Generous parental leave policy
• Health, dental, and vision insurance
• 401(k) with employer matching
• Professional growth opportunities
• Team-building activities

Pay

$150,000 - $225,000 a year

Schedule

Full-time

Benefits

• Company-wide Holidays
• Flexible vacation days
• 10 sick days
• Generous parental leave policy
• Health, dental, and vision insurance
• 401(k) with employer matching
• Professional growth opportunities
• Team-building activities