Senior Mechanical Engineer

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 and suppliers to build the energy industry of the future.

We’re in the best position to make it happen. Since 2018, we’ve raised nearly $3 billion in capital, making us the largest and leading private 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.

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.

Salary range for this full-time position + equity + benefits. The actual salary will depend on level, location, qualifications, and experience. The range displayed on each job posting reflects new hire salaries for the position across all US locations. Benefits include:

• 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

#LI-Onsite

#CFS-EX

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.

We value diversity deeply and are proud to be an equal opportunity employer by choice. We consider all qualified applicants equally, regardless of race, color, national origin, ancestry, citizenship status, protected veteran status, religion, physical or mental disability, marital status, sex, sexual orientation, gender identity or expression, age, or any other basis protected by law.