Staff Mechanical Engineer

Commonwealth Fusion Systems

Commonwealth Fusion Systems

Other Engineering

Devens, MA, USA

USD 130k-200k / year + Equity

Posted on Jun 4, 2026
About Commonwealth Fusion Systems:
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.
Join the power movement as a Staff Mechanical Engineer
The Staff Mechanical Engineer is a technical leadership role focused on the development of ports systems.
The position involves collaborating with CFS StreEng and the ports team to finalize concepts, models, and drawing releases. Additionally, the role provides production support through final delivery, including the preassembly and assembly stages in SPARC.

What you'll do:

  • Take leadership in design closure in collaboration with the ports team
  • Finalize Cad models, ensure requirements are met
  • Support procurement in preparation and execution of the contracts
  • Ensure quality and conformance and process deviations
  • Be familiar with budget and schedule to ensure on time delivery and cost management
  • Have an overall view of the work and adopt necessary measures and strategies for overall success of the project
  • Engage the team members as well as interfacing systems for full alignment and progress without hesitation

What we're looking for:

  • BS in Mechanical Engineering
  • 10+ years' relevant experience
  • Strong track record in structural analysis
  • Experience in machining complex parts
  • Knowledge of CMM; spatial and volumetric measurement
  • Advanced user of Ansys in structural analysis
  • CNC machining complex parts
  • Knowledge of CMM; spatial and volumetric measurement

Bonus points for:

  • Experience with components in vacuum
  • Experience with engineering plasma science

Must-have requirements:

  • Ability to lift up to 50 lbs occasionally
  • Perform activities such as stooping and sitting for extended periods of time
  • Willingness to occasionally travel or work required nights/weekends/on-call
  • Dedication to safety to mitigate hazards that may include heat, cold, noise, fumes, strong magnets, lead, high voltage, and cryogenics
#LI-Onsite
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.
This role requires compliance with U.S. laws concerning the export of controlled or protected technologies or information (collectively, “Export Control Laws"). Any offer of employment will be contingent on the need for compliance with such Export Control Laws.

130000 - 200000 USD a year

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