SECTION I · THE BRIEF
Brief #27961Updated 30 MAY 2026DEVENS, MALeverKHOSLA VENTURES
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Field Mechanical Engineer - Assembly

Commonwealth Fusion Systems (CFS) is an American company founded in 2018 aiming to build a compact nuclear fusion power plant based on the ARC tokamak reactor concept. The company is based in Cambridge, Massachusetts,…

Location
Devens, MA
Company size
500–2,000
Posted
2mo ago
Via
Lever
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Field Mechanical Engineer - Assembly · Commonwealth Fusion Systems

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Job title
Field Mechanical Engineer - Assembly
Job location
Devens, MA
Job description
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, 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 Field Mechanical Engineer - Assembly

As the Field Mechanical Engineer on the Assembly Team at CFS, you will be the co-owner of the SPARC assembly process. You help guide technicians through any issues that arise along the way and come up with solutions that continue work and assembly moving forward. You will proactively ensure that they have all the tools required for the work, either procuring them off-the-shelf or quickly designing and building small tools and fixtures for use. This also includes the close collaboration with adjacent teams on the Assembly Team, such as creating and incorporating the new process changes with the Assembly Process team or providing the Metrology team with any assistance or tools needed for the precision alignment of coils and other key structures. This role is on-site at Devens, MA but is a “field” role in the sense that you will be working day-to-day in the central construction hall in the CFS-2 facility where we are building the SPARC Tokamak. At the core, your role is to keep the assembly process moving smoothly in all ways using your engineering skills and knowledge to solve the many complex challenges that arise during the assembly process. You will guide how the giant parts of this multi-million pound “swiss-watch” come together!

What you'll do:
  • Co-own and be the expert in the assembly sequence of your workstation (initially this role is scoped to the assembly of the Toroidal Field Coil (TF) semicircle sub-assemblies), with the responsibility to determine and enact acceptable solutions and changes to the sequence that both allow successful completion of the work-station but also fit with the entire SPARC assembly sequence
  • Be responsible for new first-encounter work scope definition including the installation of various manifolds and magnet sub-assemblies
  • Determine and execute solutions for identified assembly issues that arise, such as fit, method, or component handling problems. Work with the Tokamak System design teams to determine how a part or process step could be modified to work while also meeting functional requirements
  • Proactively procure or build all tools, fixtures, or manipulation equipment required for the upcoming ports of the process in your workstation
  • Serve as the owner for a process by testing, implementing, and handing off to production technicians for repeated use for any given operation or tool(s)
  • Provide design feedback to SPARC sub-system designs with a focus on manufacturing and assembly. Participate in both formal and informal design reviews to ensure what is delivered can be assembled
  • Assist in the disposition and resolution of non-conformance issues on parts or the process, then working to incorporate and release red-line changes into an updated assembly sequence.
  • Support hands on operations during Tokamak Assembly serving a variety of roles in the process
  • Work with teammates in a collaborative fashion to receive feedback early and often to ensure all requirements are met. Many SPARC projects involve high loads, vacuum requirements, and complex manipulation requiring the involvement and review of adjacent sub system experts
  • What we’re looking for:
  • Civil, Mechanical, or Aerospace Engineering B.S. with 5 years' experience
  • 3+ years' of Mechanical Engineering Experience demonstrating project ownership
  • 2+ years' experience overseeing an in-progress construction, manufacturing, or assembly/integration process
  • 2+ years' of experience with CAD software
  • Bonus points for:
  • 6+ years of Mechanical Engineering Experience demonstrating project ownership
  • Experience with Siemens NX
  • Lifting operations experience
  • Knowledge of welding
  • Knowledge of piping and tubing construction and joining
  • Experience with highly complex or delicate assemblies
  • Experience with assembly or integration in tightly packaged spaces
  • Experience with fast-paced and dynamic construction, manufacturing, or assembly/integration builds
  • Experience with composite preparation, layup, and curing.
  • Experience with cable, tubing, bracing alignment and securing
  • Experience with fiber inspection and splicing work and equipment
  • Heavy component manipulation of large structures
  • Must-have Requirements:
  • Ability to occasionally lift up to 50 lbs
  • Perform activities such as typing, standing, stooping, climbing or sitting for extended periods of time
  • Required onsite 5 days/week when assembly operations with relevant tools are underway, with possible alternating first or second shift assignment
  • 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
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    Where this role is based

    Devens, MA

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    Commonwealth Fusion Systems headquarters

    Cambridge, MA

    Company size

    5002,000 employees

    Founded

    2018

    Total raised

    $3,877,000,000

    View company profile ↗

    Funding rounds

    • Series Unknown$1B
    • Series B$863M
    • Grant$15M
    • Series B$1.8B
    • Series A$84M
    • Series A$115M