or apply directly on Hexium's site. We never take the application ourselves.
Is this posting real?
- This role has been open
- 5 days Hexium's roles stay open a median of 37 days
- Reposted
- No
- Salary listed
- No 0% of Hexium's roles list one
- Ghost-job risk at Hexium
- moderate 1 stale, 0 reposted of 3 open
- Hiring momentum
- 7 roles opened in the last 90 days ↑ up vs. the prior 90 days
- Last confirmed on the employer's board
- 2026-09-17
Measured from postings appearing on and disappearing from Hexium's own greenhouse board since 2026-08-03. Full hiring picture for Hexium.
About this role
As a Senior Mechanical Engineer at Hexium, you will lead the modernization of mechanical designs for Atomic Vapor Laser Isotope Separation (AVLIS) technology. Your responsibilities include reviewing legacy designs, creating modern 3D CAD assemblies, and collaborating with scientists to resolve technical challenges. This role will initially be based at Lawrence Livermore National Laboratory and will transition to a Hexium production facility as the program progresses.
- benefits
- 3/5
- freshness
- 5/5
- career value
- 4/5
- role clarity
- 4/5
- pay transparency
- 0/5
Scored from the posting itself — how clearly the role is described, how much it says about pay and benefits, and how recently it was listed. Not a judgement of Hexium as an employer.
What you need
- 6+ years of mechanical engineering experience, including vacuum system design and/or precision mechanical hardware
- Bachelor's degree in Mechanical Engineering or closely related field
- Proficiency in 3D CAD (SolidWorks, Creo, or similar)
- Must currently hold an active DOE Q clearance or active DOD Top Secret clearance, or have held DOE Q / DOD Top Secret clearance within the past 18 months
- Must be a U.S. Person (required for access to export-controlled technical data)
- Willingness to work on-site full-time at Lawrence Livermore National Laboratory initially, with required relocation to Hexium's production facility as the program progresses
Nice to have
- Experience with specialty alloys and refractory metal fabrication
- Experience with high-temperature vacuum processes
- FEA/thermal simulation experience
- Background in safety-critical hardware (aerospace, nuclear, defense)
What you get
- Stock Options
- Paid Time Off
- 401(k) Matching
- Medical, Dental, Vision insurance
- HSA & FSAs
Worth weighing
- Role requires relocation to a production facility that is not yet determined
- On-site work at a DOE national laboratory involves standard security and classified-handling protocols
- Physical requirements include extended periods of close visual focus and working in confined spaces
Summarised from Hexium's posting. Read the full original.
Listed by Hexium on their greenhouse job board, last confirmed open on 2026-09-17. PitchMeAI is not the employer.