Mechanical Design Engineer
Confirmed on the employer's own hiring board on Oct 19, 2026. First seen by Alion on May 4, 2026. Pacific Fusion scores A on the Alion truth index.
About Pacific Fusion
Pacific Fusion was founded in 2023 with the mission to power the world with abundant, affordable, clean energy.
We are rapidly designing and building a pulser-driven inertial fusion system to achieve net facility gain (more fusion energy output than stored energy input). In parallel, we are developing the key components required to build affordable fusion systems.
Our plans are ambitious. We have raised over $900M so far from incredible investors, resourcing us to deliver on these plans. We are bringing together the best scientists, engineers, and operators from the fusion community, hard tech industry, and other sectors. We are united by a shared sense of urgency to provide clean power for the world, particularly managing climate change while meeting growing global energy demand. You can read more about us in this letter from our founders.
Why This Role Matters
As aMechanical Design Engineer, you will help with the design, development, and integration and validation of mechanical components and systems integral to our advanced fusion energy systems. This role requires a top-tier combination of technical expertise, problem-solving skills, and a proactive mindset to meet the exciting challenges in the field of fusion energy.
Responsibilities:
Design and analyze large, high-performance vacuum seals for water-to-air, air-to-high-vacuum, and water-to-high-vacuum transitions
Lead experimental design and testing in collaboration with internal teams, external vendors, and academic partners
Conduct research into novel sealing techniques; define, execute, and evaluate test campaigns
Perform FMEA and tolerance stack-up analyses to ensure seal reliability and system safety
Design test assemblies and risk-reduction
Review and present technical work across multidisciplinary teams; contribute to system-level integration discussions
Provide subject-matter expertise in sealing strategies and help guide the integration of systems in the target area
Document sealing processes, validation data, and lessons learned
Mentor and support junior engineers on design and integration challenges
Qualifications:
Bachelor's or Master's degree in Mechanical, Aerospace, or a related engineering field, or equivalent experience
5+ years of mechanical design experience with a focus on vacuum seals and systems, including rough, high, and ultra-high vacuum environments
Strong proficiency in CAD, FEM, and engineering analysis tools
Proven expertise in tolerance analysis, FMEA, seal design, and mechanical integration
Pay Range:
$138,100—$263,800 USD
TOTAL COMPENSATION AND BENEFITS FOR ELIGIBLE EMPLOYEES
Industry-competitive salary
Equity plan
6% employer 401k matching
Generous paid time off (including sick leave, vacation, paid family leave)
Medical, Dental, and Vision insurance
Actual base salary offered will be determined by: experience, skills, and work location. This range is for base salary, our total compensation includes equity and benefits. We welcome you to apply even if your expectations are outside our listed range.
EQUAL OPPORTUNTITY
Pacific Fusion is committed to creating a diverse environment and is proud to be an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status.
Pacific Fusion is committed to providing reasonable accommodations for qualified individuals with disabilities in our job application procedures and throughout employment. If you need assistance or any accommodation, please let us know.
U.S. EXPORT CONTROL COMPLIANCE
This position may require access to information or technology that is subject to U.S. export control laws, such as ITAR or EAR. Under these regulations, we are required to ensure that such access is provided only to individuals who are classified as 'U.S. Persons.'This status includes U.S. citizens, U.S. nationals, lawful permanent residents (green card holders), and asylees and refugees with such status granted, not pending.
RECRUITING AGENCIES
Pacific Fusion does not accept unsolicited resumes from recruiters or employment agencies without a fully executed recruitment agreement in place. In the absence of such agreement, Pacific Fusion reserves the right to pursue and hire any candidates without an obligation to pay fees. Agencies are requested not to contact Pacific Fusion hiring managers or employees regarding recruiting services.