Role
Commonwealth Fusion Systems is hiring a Field Mechanical Engineer - Assembly to co-own the SPARC tokamak assembly process from the central construction hall of its CFS-2 facility. The engineer helps technicians resolve issues, supplies or quickly designs the tools and fixtures they need, and supports the assembly process and metrology teams.
Responsibilities: Become the expert in a workstation's assembly sequence, initially toroidal field coil semicircle sub-assemblies, and decide acceptable changes that fit the overall SPARC sequence. Define first-encounter work scope, including manifold and magnet sub-assembly installation, and resolve fit, method or handling problems with tokamak system design teams. Procure or build tools and fixtures, prove out processes before handing them to production technicians, give design-for-assembly feedback, disposition non-conformances and release red-line changes.
Requirements: A BS in civil, mechanical or aerospace engineering with five years of experience. This must include at least three years of mechanical engineering experience demonstrating project ownership, at least two years overseeing an in-progress construction, manufacturing or assembly and integration process, and at least two years of CAD experience.
Preferred experience: Six or more years of mechanical engineering project ownership; Siemens NX; lifting operations; welding; piping and tubing joining; complex, delicate or tightly packaged assemblies; fast-paced builds; composite layup and curing; cable and tubing alignment; fiber inspection and splicing; and heavy component manipulation.
Working arrangements: The engineer must be onsite five days a week when assembly operations with relevant tools are underway, with possible alternating first- or second-shift assignments. The work involves occasional lifting up to 50 lbs, stooping and climbing, with industrial hazards including strong magnets, high voltage, high current and cryogenics. Any offer depends on compliance with U.S. export-control laws.
Snapshot
| Employer | Commonwealth Fusion Systems |
| Workplace | Devens, Massachusetts, US |
| Onsite | Onsite |
| Employment type | Full-time |
| Salary | $90,000–$145,000 a year |
| Date posted | 2026-05-30 |
| Expires | — |
| Verified | 2026-10-06 |
Sources & verification
The original publication date is exactly as posted on the employer ATS — no substitutions. The links below are the same ATS pages we used to verify this listing; the dates come from when we last checked them.
- Last checked