Lead Technician, Assembly Testing
Commonwealth Fusion Systems
Company Overview
Commonwealth Fusion Systems (CFS)
HeadquartersCambridge, MA, United States
Founded2018
SizeApproximately 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 Lead Technician, Assembly Testing
The Mechanical Commissioning Field Lead is responsible for leading a small team (2-3 technicians) in the execution of SASY testing activities under the direction the Manger of Assembly Testing with guidance and support from Test Engineering. These activities may also include assembly activities, as testing will take place in parallel with SPARC assembly. The lead technician will have daily hands-on responsibilities.
What you'll do
- Execute complex testing procedures in the field with a primary focus on mechanical testing to include pneumatic pressure proofing and leak detection using helium leak detector.
- Work under the direction of Manager, Assembly Testing, to execute test procedures.
- Serve as front line supervisor for test technicians by providing guidance and instruction to technicians to facilitate safe, effective, and efficient execution of work.
- Identify issues and potential issues pro-actively, ensure accurate submission to our work and quality management systems and assist to drive issues to successful conclusions.
- Ensure completion of all test documentation in an accurate and timely fashion.
- Coach technicians to embody the CFS behaviors and guiding principles in all interactions.
- Represent the SASY Test team in collaboration with all CFS cross-functional teams as required.
- Adhere to the highest standards of safety and ensure that activities taking place are being performed in accordance with CFS safety policies and applicable regulatory safety standards.
What we're looking for
- HS Diploma.
- Minimum 5 years of hands-on mechanical testing experience, with a heavy focus on pneumatic pressure proofing and helium leak detection using mass spectrometers.
- Proven experience leading small to medium-sized crews of technicians performing complex mechanical or testing activities.
- Demonstrated experience with high-vacuum hardware: Must be proficient in plumbing temporary test fixtures and making connections using KF, CF, VCR, compression fittings, and NPT.
- Familiarity with setting up and connecting vacuum systems, including turbomolecular pumps and leak detectors.
- Mid-level proficiency in with Microsoft or Google productivity software.
Bonus points for
- Formal training (40+ hours) or active progression toward an ASNT Level II NDT certification in Leak Testing.
- Direct experience with specific leak testing methodologies (e.g., tracer probe, hood technique, and helium-filled object techniques).
- Prior experience working in fusion-relevant, aerospace, or semiconductor cleanroom environments.
- Experience with low or high voltage electrical testing.
Must-have requirements
- Ability to occasionally lift up to 50 lbs.
- Perform activities such as stooping, climbing, typing, standing, or 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.
- Willingness to travel or work required nights/weekends/on-call occasionally.
$36 - $41 an hour
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.
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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.
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About the role
September 9, 2026
September 9, 2026
Full time
On-site
Company
US$36–41 hourly
- Devens, Massachusetts, United States
Minimum 5 years of hands-on mechanical testing experience
UTC-05:00