Commonwealth Fusion Systems

Senior Mechanical Engineer - Cable Magnets

Join Commonwealth Fusion Systems in Devens, Massachusetts as a Senior Mechanical Engineer focusing on cable magnet hardware design and production. Lead design, analysis, and manufacturing support for fusion energy projects. Enjoy competitive pay, equity, flexible vacation, and strong benefits in a mission-driven environment.
Commonwealth Fusion Systems
Commonwealth Fusion Systems
Devens, Massachusetts, United States Hybrid Full time US$110,000–185,000 annually UTC-05:00

Commonwealth Fusion Systems

Company Overview

Name

Commonwealth Fusion Systems (CFS)

Headquarters

Cambridge, MA, United States

Founded

2018

Size

Approximately 430 employees (source: zoominfo.com). Revenue figures vary, with reports indicating $211.3 million or $31.7 million, though as a pre-revenue fusion developer focused on R&D, these may reflect funding or operations rather than sales.

What They Do

Commonwealth Fusion Systems (CFS) is a pioneering private fusion energy company that specializes in tokamak-based magnetic confinement fusion. Founded as a spinout from MIT's Plasma Science and Fusion Center, CFS focuses on utilizing high-temperature superconducting magnets to achieve commercial net energy production (source: cfs.energy). The company has made significant strides in its technology, particularly with the development of compact fusion machines that leverage decades of tokamak science. Their flagship projects, SPARC and ARC, aim to demonstrate net energy gain and commercial viability in the coming years (source: cfs.energy).

Projects & Track Record

CFS is currently engaged in several groundbreaking projects, most notably the construction of SPARC, which is set to be the world's first net-energy fusion machine. Located at their Fusion Energy Campus in Devens, Massachusetts, SPARC aims to demonstrate net energy gain by the late 2020s (source: cfs.energy). Additionally, CFS is planning the ARC project, a 400 MW-class grid-scale tokamak power plant designed for commercial deployment in the early 2030s. These projects are underpinned by significant technological advancements, including the successful testing of the central solenoid magnet module (CSMC) in November 2024, which confirmed the manufacturability of critical components for SPARC (source: zoominfo.com).

Recent Developments

In the past two years, CFS has made remarkable progress, including the opening of its Devens Fusion Energy Campus on February 10, 2023, which was attended by notable figures such as U.S. Secretary of Energy Jennifer Granholm (source: cfs.energy). The company has also secured substantial funding, raising $863 million in August 2024, building on a previous $1.8 billion round in May 2023, bringing total funding to over $2 billion (source: wbjournal.com). Furthermore, CFS announced its first commercial power plant site in Chesterfield County, Virginia, which will be independently financed and operated, with plans for grid connection in the early 2030s (source: zoominfo.com).

Working There

CFS offers a range of roles across various disciplines, including fusion science, engineering, manufacturing, and materials science. The majority of their workforce is based at the Devens campus, which has grown to over 430 employees (source: cfs.energy). The company culture emphasizes rapid execution and transparency, attracting top talent from the fusion and manufacturing sectors. Key executives include Co-Founder and CEO Bob Mumgaard, along with other leaders in operations and science, indicating a strong demand for expertise in tough tech and physics (source: nasdaqprivatemarket.com). While specific benefits are not detailed, the scale-up and investor backing suggest competitive packages for high-caliber roles in a mission-driven environment (source: cfs.energy). Job seekers are encouraged to monitor their careers page for openings related to SPARC and ARC advancements.


Last updated on Feb 23, 2026 | Report an issue

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 - Cable Magnets

As a Senior Mechanical Engineer for the Cable Magnets Engineering team, you will own hardware from early concepts to delivery. You will develop the design, performing thermal, structural, and electromagnetic analysis to ensure the hardware meets requirements. You will develop design notes, technical specifications, and other documentation necessary to manufacture and install the Cable Magnet hardware and supporting systems. In your role you will also support procurement in the preparation and execution of manufacturing contracts, and support CFS production and assembly teams through build and installation of your designs.

What you'll do

  • Act autonomously as the primary owner of cable magnet hardware for SPARC, ARC, or other projects, ensuring designs are completed, validated, procured, built, and installed correctly and on time
  • Produce new and iterate on existing design concepts, using a deep understanding of physics, structural mechanics, and analysis techniques for both metallics and composites
  • Liaise with partner teams such as R&D, analysis, manufacturing, and procurement to drive completion of program milestones in a timely fashion
  • Diagnose issues on the production and assembly line and provide immediate path forward based on known understanding of hardware. Propose and implement design solutions based on root cause
  • Prepare reports, presentations, and other documentation to serve as design documentation and validation of final Cable Magnet systems
  • Mentor junior engineers and assist in establishing and implementing engineering best practices

What we're looking for

  • Bachelor's degree in mechanical engineering, aerospace engineering, or another relevant field
  • A minimum of 7 years of engineering design and analysis experience is required, including at least 2 years providing engineering support to production hardware in the form of resolving technical issues and implementing design for manufacturing or assembly changes
  • Relevant hands-on experience in the form of parts designed for high loads and/or extreme environments
  • Excellent fundamental knowledge of mechanical systems such as static structures and heat transfer (required)
    Familiarity with all steps in the design process with an emphasis on creativity, simplicity, and execution (required)
  • Be self-motivated, committed to self-growth, and exhibit excellent problem-solving skills (required)
  • CAD proficiency (required) NX preferred, any acceptable
  • FEA (required) ANSYS and COMSOL preferred
  • Expertise in AMSE Y14 GD&T principles (preferred)

Bonus points for

  • Demonstrated record of design of mechanical components beyond desktop scale. E.g. high power (MW+), high mass (ton+), high force (MN+)
  • Experience in production or heavy equipment assembly environments
  • Design experience with
    Electromagnets
    Vacuum systems
    Welding
    Composite materials
    Radiation environments
    Cryogenic environments

Must-have requirements

  • Perform activities such as sitting for extended periods of time
  • Work in a facility that contains industrial hazards including heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, high current, pressure systems, and cryogenics
  • Perform activities such as sitting for extended periods of time
  • Occasional travel, occasional nights/weekends/on-call

$110,000 - $185,000 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

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.

Apply now

Job expired?

Please let Commonwealth Fusion Systems know you found this job on Rejobs. It helps us grow and get more people working in renewable energy.

About the role

August 26, 2026

August 26, 2026

Full time

Hybrid

Company

US$110,000–185,000 annually

Hydrogen

Commonwealth Fusion Systems

cfs.energy

  •  Devens, Massachusetts, United States

Minimum of 7 years of engineering design and analysis experience required.

UTC-05:00