Commonwealth Fusion Systems
Direct Lever career site

R&D Test Engineer - Fluid Systems

Location
Devens, MA · On-site
Job type
Full-time
Level
Senior
Experience
5+ years
Education
Bachelor's degree
Listed
14 days ago

Skills & highlights for this role

  • Fluid systems design
  • Mechanical engineering
  • Chemical engineering
  • Process engineering
  • Thermofluid systems
  • Hand calculations
  • System-level analysis
  • Process flow diagrams (PFDs)
  • Piping and instrumentation diagrams (P&IDs)
  • Instrumentation design
  • Component specification
  • Commissioning

Also useful

  • ANSYS
  • COMSOL
  • 1D compressible flow codes
  • Python
  • MATLAB
  • Structural simulation
  • Thermal simulation
  • Cryogenic systems

What you'll do

  • Design fluid systems for test stands that meet test objectives/requirements, soliciting feedback from interfacing teams as necessary
  • Challenge requirements as necessary to achieve simplicity in design and develop efficient de-risking strategies and plans
  • Perform hand calculations and system level analyses demonstrating sufficient margin for fluid system requirements; build and run Ansys structural and thermal simulations on components and assemblies
  • Procure off-the-shelf process fluid components, manage relationships with vendors, draft specifications for speciality parts and design custom fluid system components as needed
  • Manage the build and commissioning of fluid systems, coordinating engineers and technicians to safely bring systems to operational status
  • Design system instrumentation and automation for safe operations

What we're looking for

  • Bachelor's degree in mechanical, chemical, process engineering, or a closely related field
  • 5+ years of experience in the engineering of integrated fluid/mechanical systems (experience with both small-scale rapid R&D and large-scale systems is highly desired)
  • Full-lifecycle fluid systems:
  • Hands-on experience executing the entire lifecycle of large-scale thermofluid systems
  • Component expertise:
  • Experience developing specifications, sizing and working with tanks, process piping, pumps, valves, compressors, purification stages, circulators, heat exchangers, etc.
  • Design documentation:
  • Strong background in establishing system requirements, generating process flow diagrams (PFDs), and developing piping and instrumentation diagrams (P&IDs)
  • Instrumentation:
  • Experience in the design, integration, and troubleshooting of system instrumentation
  • Software and analysis tools:
  • Experience utilizing engineering tools such as ANSYS, COMSOL, 1D compressible flow codes, Python and MATLAB
  • Extreme environments:
  • Practical experience designing, building, and commissioning fluid systems for specialized pressurized, cryogenic, vacuum, and/or elevated-temperature applications
  • Vendor relations:
  • Experience sourcing complex components, drafting technical specifications, and managing relationships with specialized vendors and suppliers
  • Cross-functional communication:
  • Strong ability to distill complex fluid system details and effectively communicate to non-experts and interfacing teams across R&D, production, and procurement
  • Problem solving:
  • Highly driven to challenge assumptions, make efficient technical decisions, and develop innovative solutions on tight timelines

Bonus points for

  • Adaptability:
  • Ability to flex into adjacent engineering disciplines, such as structures or materials, when required to help retire risks for SPARC and ARC
  • Process optimization:
  • Strong aptitude for identifying bottlenecks and improving throughput during system designs, builds, and commissioning operations

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
  • Dedication to safety to mitigate industrial hazards that may include heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, and cryogenics
  • Willingness to travel or work required nights/weekends/on-call occasionally
  • #LI-Onsite
  • 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.

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.

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 an R&D Test Engineer

The role of an R&D Test Engineer is to develop novel fluid systems for R&D test stands, with a major focus on supporting magnet testing. The range of process fluids is broad (liquid, gaseous, cryogenic, supercritical, molten salt, etc.), requiring strong mechanical and chemical engineering fundamentals. The ideal candidate will be resourceful-combining industry best practices, off-the-shelf and customized hardware, and creativity to deliver these fluid systems on tight timelines.

Projects will be on varying scales, from smaller-scale test stands and deep system analysis to larger, complex projects as needed for SPARC and ARC. In addition to designing and building, the engineer will actively operate as a test engineer to commission systems and design automation alongside a team of test/software engineers and operators. You must work collaboratively across production, R&D, procurement, and the SPARC team.

Various projects will also require flexing outside of traditional fluids engineering into other disciplines, such as structures and materials engineering, to successfully retire risks for SPARC and ARC.

Read the original posting

From Commonwealth Fusion Systems's careers page, first listed on Rolev.ai on October 26, 2026. Rolev.ai is not the employer.

How Rolev.ai helps with this application

Rolev.ai is a job search and application tool for US job seekers. For this R&D Test Engineer - Fluid Systems role at Commonwealth Fusion Systems, it shows how your resume fits, tailors your resume to the posting, and prepares the application for you to review.

  • See how you fit

    Openings from employer career sites are ranked against your whole resume—and searchable inside Claude, ChatGPT, and Cursor via Rolev.ai MCP.

  • Tailor without inventing

    Every change to your resume is checked against your original. New experience goes in only with your yes—zero fabricated claims.

  • Draft the full kit

    Tailored and Full Match resumes, role-specific cover letters, and answers to employer screening questions are prepared in seconds.

  • 1-Click Extension Autofill

    The Chrome extension fills the employer's Greenhouse, Workday, Lever, or Ashby form in 1 click. You review it and press Submit.

Common questions

Where is the R&D Test Engineer - Fluid Systems job at Commonwealth Fusion Systems located?

This R&D Test Engineer - Fluid Systems position at Commonwealth Fusion Systems is located in Devens, MA (On-site). Always check Commonwealth Fusion Systems's application page for specific state eligibility or relocation policies.

What qualifications are required for R&D Test Engineer - Fluid Systems at Commonwealth Fusion Systems?

For the R&D Test Engineer - Fluid Systems role, Commonwealth Fusion Systems highlights 5+ years of relevant experience; a bachelor's degree; experience with Fluid systems design, Mechanical engineering, Chemical engineering, Process engineering, Thermofluid systems, Hand calculations. Rolev.ai can score your existing resume against these requirements and show any skill gaps before you apply.

How do I apply for the R&D Test Engineer - Fluid Systems position at Commonwealth Fusion Systems?

This listing links directly to Commonwealth Fusion Systems's Lever application page. You can apply directly on Commonwealth Fusion Systems's site, or use Rolev.ai to check your resume fit, generate a zero-hallucination tailored resume and cover letter for this posting, and autofill the Lever application form in 1 click with the Rolev.ai Chrome extension. You always review the form and press Submit yourself.