Senior Mechanical Engineer

What we’re looking for

• Bachelor's degree in Mechanical Engineering or related field (or equivalent industrial experience)
• 8+ years of experience with 7+ years of experience working as a senior mechanical design engineer or engineering team lead in a relevant context: design and implementation of R&D systems and manufacturing equipment
• Ability to conceive of novel solutions for complex engineering systems in challenging environments
• Expertise with 3D modeling; preferred experience with SolidWorks and NX
• Experience with COMSOL, ANSYS or other FEA tools
• Ability to select and qualify vendors for components or subsystems
• Demonstrated ability to lead in either direct or matrix structures
• Strong verbal and written communication skills and a dedication to high-quality documentation

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

At CFS, we excel in fast-paced environments, driven by our values of integrity, execution, impact, and self-critique. As we grow, we’re eager to bring on mission-driven folks who offer diverse perspectives and fresh ways to tackle challenges.

• Prior success building first-of-kind or experimental tools for material science or semiconductor R&D
• Familiarity in applying Semi-S8, ASME, ACI, ASTM, and other mechanical standards to design solutions
• Experience with the operation of equipment in a manufacturing environment

Commonwealth Fusion Systems is on a mission to deliver the urgent transition to fusion energy.

Combining decades of research, top talent, and new technologies, we’re designing and building commercially viable fusion power plants. And we're working with policymakers, suppliers, and many others to build the energy industry of the future.

We’re in the best position to make it happen. Since 2018, we’ve raised $4 billion of capital, making us the largest and leading fusion company in the world.

Now we’re looking for more thinkers, doers, builders, and makers to join us. People who’ll bring new perspectives, solve tough problems, and thrive as part of a team.

If that’s you and this role fits, we want to hear from you.

Join the power movement as a Senior Mechanical Engineer

We’re looking for a Senior Mechanical Engineer to join our R&D and equipment design team to help build the next generation of thin-film deposition technology. The Senior Mechanical Engineer will be responsible for the design and implementation of advanced R&D equipment and complex machinery. This role requires strong technical expertise, procedural discipline, and the ability to collaborate across engineering and technology functions to ensure safe, reliable, and high-performance equipment.

If you enjoy working on complex design problems, mentoring others, and solving problems in a collaborative, fast-paced environment, this is your opportunity to make an impact.