Senior Mechanical Engineer

Number of employees

1050

Devens, MA, USA

Posted on: 2026-04-09

Category: renewables

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Employment type:

Full time

Experience required:

Senior

Salary

Salary not provided

About the company:

Commonwealth Fusion Systems (CFS) is on a mission to deliver clean fusion energy to the planet fast enough to matter for humanity’s biggest challenges.

It’s urgent. The gap between the energy we need and the energy we have is widening every day. Fusion is a critical part of the energy transition away from fossil fuels, a new chapter for the world’s energy supply.

We’re committing to delivering fusion power plants and a full-fledged fusion energy industry as we’ve delivered on other promises. Like the world’s strongest high-temperature superconducting magnet, the game-changing technology that’s making commercial fusion energy a reality.

We’ve raised over $2 billion in capital — more than any other fusion energy company — and attracted top talent to design, build, and deliver commercial  fusion power plants. And we’re working with policymakers and suppliers to make fusion energy available globally.

As we push toward the fusion-energy future, we’ll keep setting and meeting milestones, sharing and validating our progress, and encouraging others to do the same.

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 Senior Mechanical Engineer

We are seeking a highly motivated and experienced Mechanical Engineer to join our manufacturing team. In this role, you will be responsible for providing technical expertise during the commissioning, implementation, and integration of manufacturing equipment. You will work closely with our production team to ensure that our manufacturing processes are optimized for efficiency, quality, and safety.

#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.

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.

What you'll do:

  • Provide technical expertise during the commissioning, implementation, and integration of manufacturing equipment
  • Support Factory Acceptance Testing (FAT) and Site Acceptance Testing (SAT) of equipment
  • Troubleshoot mechanical issues and provide solutions to ensure equipment operates efficiently
  • Collaborate with production and engineering teams to optimize manufacturing processes and improve equipment performance
  • Drive continuous improvement initiatives for manufacturing equipment to increase efficiency, reduce downtime, and improve quality.
  • Conduct root cause analysis and implement corrective actions to resolve manufacturing issues
  • Ensure compliance with all safety requirements
  • Work with external vendors and suppliers to ensure the timely delivery of equipment and materials
  • Conceptualize and detail new manufacturing equipment for scaled up manufacturing processes
  • Run experiments to determine the feasibility of new manufacturing processes and translate those learnings into practical designs

What we're looking for:

  • Bachelor's degree in Mechanical Engineering or a related field
  • 7+ years of experience in mechanical engineering, with a focus on manufacturing equipment
  • 5+ years of manufacturing equipment and tooling design
  • Strong knowledge of mechanical systems, including hydraulics, pneumatics, and motion control
  • Experience with 3D CAD packages and 2D drawings
  • Experience with Factory Acceptance Testing (FAT) and Site Acceptance Testing (SAT) of equipment
  • Understanding of GD&T and its application
  • Excellent problem solving and analytical skills
  • Strong communication and interpersonal skills, with the ability to collaborate effectively with cross-functional teams
  • Experience with commissioning and startup of manufacturing equipment
  • Bonus points for:

  • Strong knowledge of mechanical systems, including hydraulics, pneumatics, and motion control
  • Experience developing manufacturing equipment and tooling for a novel process
  • Experience with production ramp-up and optimization of manufacturing processes
  • Experience with automated equipment and robotics
  • Must-have requirements:

  • Ability to lift up to 50 lbs occasionally
  • Perform activities such as typing, standing, 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
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