Dimensional Engineer – SPARC

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 Staff Dimensional Engineer – SPARC

SPARC is a first-of-a-kind machine, and it presents some of the hardest dimensional management problems in industry today: large high-field magnets, tight tolerances on complex geometries at meter scale, novel materials, and assembly stack-ups with no precedent to copy from. CFS is seeking a Staff Dimensional Engineer to be the technical authority for dimensional management across HTS Magnet production and the SPARC project.

This is a role for someone who wants to define a discipline, not inherit one. You will own how design intent becomes buildable, verifiable hardware: setting GD&T and datum strategy with Engineering, analyzing variation propagation through assembly sequences before hardware proves it the hard way, and defining what we measure and to what acceptance criteria. Your decisions will shape how fusion hardware is toleranced, measured, and accepted, on SPARC and on the ARC power plants that follow.

You will work alongside a metrology team equipped with laser trackers, portable CMM arms, and structured-light scanning, and with an established Quality Engineering organization that owns statistical process control and measurement system analysis, so your focus stays on the geometry.

• Set GD&T and datum strategy in partnership with Engineering, translating design intent into tolerancing that is functionally sound and manufacturable with our equipment and fabrication methods
• Perform tolerance stack-up and 3D variation analysis on large complex assemblies, predicting variation propagation through build sequences and informing tooling, indexing, and assembly strategy
• Architect inspection requirements for large metallic components and assemblies, defining what to measure, how, and to what acceptance criteria
• Drive key characteristic identification and flowdown from top-level assembly requirements to component drawings and supplier requirements
• Support disposition of Non‑Conformance Reports with dimensional analysis, quantifying the assembly‑level impact of as‑built deviations to inform use‑as‑is, rework, repair, or scrap decisions
• Review engineering change packages for dimensional impact as designs mature through SPARC assembly and integration
• Coach QC Inspectors, Quality Engineers, and Design Engineers on GD&T interpretation and dimensional management practice

• BS in Mechanical, Industrial, Materials Science, Manufacturing, or Aerospace Engineering
• 10+ years of dimensional engineering experience on complex hardware (airframes, vehicle structures, turbo machinery, large equipment, or comparable)
• Mastery of GD&T (ASME Y14.5) as an author, not only an interpreter: datum strategy, tolerance allocation, and drawing review authority; GDTP certification strongly preferred
• Proven tolerance stack‑up capability, both 1D (RSS, worst‑case) and 3D variation analysis (3
  
  DCS, VisVA, or equivalent
• Experience applying dimensional management to large assemblies: indexing…