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Commonwealth Fusion Systems

Subassemblies Technician (m/w/d)

Become a Subassemblies Technician with Commonwealth Fusion Systems in Devens, Massachusetts. This role involves building precision subassemblies for fusion energy projects, ensuring high quality and cleanliness. Enjoy a competitive hourly wage of $35 - $43 and the chance to work on groundbreaking technology in a diverse and inclusive environment.
Commonwealth Fusion Systems
Commonwealth Fusion Systems
Devens, Massachusetts, United States   On-site   Contract Position   USD 35–43 per hour  UTC-05:00

Commonwealth Fusion Systems

Company Overview

Commonwealth Fusion Systems (CFS)

Cambridge, MA, United States

2018

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.

Contact


Last updated on 2026-01-02 | 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 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 Subassemblies Technician

The Subassemblies team is responsible for delivering precision, ultra high vacuum subassemblies for ten major teams that go into the SPARC Tokamak. As a Subassemblies Technician, you will be the last set of hands and eyes on critical parts; as such, meticulous attention to detail in build quality is necessary. You will draw upon your years of technical experience building complex systems to deliver the best possible parts. This role is truly a once in a lifetime opportunity to use hands-on assembly skills to accelerate the development of fusion energy by ensuring SPARC is built on time and to high quality. The main systems you will be building are high power RF antennas, plasma facing components, port plugs, error field correction coils, vertical stability coils and plasma diagnostics; the bespoke tools used for real-time control of a burning plasma and to achieve SPARC's science mission.

What you'll do

  • Build complex and simple subassemblies and components while maintaining all cleanliness specifications
  • Perform testing and check-outs with helium leak checking and various other check-out equipment
  • Assist with precision alignment and installation of active and passive optical systems
  • Actively participate in maintaining mandatory cleanliness of work area and clean room
  • Assist other CFS teams with related skilled work

What we're looking for

  • High school diploma or equivalent experience
  • 7 years in a highly technical assembly role; e.g., aerospace/aircraft, racing, semiconductor, oil & gas, laboratory, wind, automotive
  • Can operate a forklift
  • Experience completing large scale projects end to end
  • Experience using measurement tools
  • Experience using JIRA, Manufacturo, or other software based tracking
  • Highly self-motivated, organized, and passionate about their work

Bonus points

  • Welding experience
  • Knowledge of clean room best practices
  • Knowledge of cryogenic systems
  • Knowledge of six sigma process
  • Wiring and soldering experience

Essential Requirements

  • Ability to occasionally lift up to 50 lbs
  • Ability to perform activities such as sitting, climbing, stooping, typing, and standing for extended periods of time
  • Willingness to occasionally travel for required nights/weekends/on-call
  • Dedication to safety to mitigate industrial hazards that may include heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, and cryogenics

$35 - $43 an hour

This is a contract position.

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.

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About the role

November 20, 2025

Contract Position

Company

January 2, 2026

On-site

USD 35–43 per hour

Commonwealth Fusion Systems

cfs.energy

  •  Devens, Massachusetts, United States

7 years in a highly technical assembly role

UTC-05:00

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