Mechanical Design Engineer

Pacific Fusion; San Leandro (CA); On-site; USD 138,100 - 263,800; Full time

Benefits offered by this job

Industry-competitive salary

Equity plan

6% employer 401k matching

Generous paid time off

Medical, Dental, and Vision insurance

Job summary

Pacific Fusion in San Leandro is looking for a Senior Mechanical Engineer to lead the design and integration of vacuum seals for their pulsed magnetic inertial fusion platform. The role requires over 8 years of experience in mechanical design, specifically with vacuum systems. Responsibilities include designing seals, leading experimental testing, and mentoring junior engineers. The position offers an industry-competitive salary and comprehensive benefits including equity options and generous paid time off.

Qualifications

• Bachelor's or Master's degree in Mechanical, Aerospace, or a related engineering field, or equivalent experience.
• 8+ years of mechanical design experience with a focus on vacuum seals and systems.
• Strong proficiency in CAD, FEM, and engineering analysis tools.

Responsibilities

• Design and analyze large, high-performance vacuum seals for various interfaces.
• Lead experimental design and testing of vacuum seals.
• Conduct research into novel sealing techniques and evaluations.
• Perform FMEA and tolerance stack-up analyses.
• Design test assemblies for seal validation.
• Mentor and support junior engineers.

Skills

Mechanical design experience

Proficiency in CAD

Proficiency in FEM

Tolerance analysis

FMEA expertise

Seal design

Education

Bachelor's or Master's degree in Mechanical, Aerospace, or related field

Job description

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 a Senior Mechanical Engineer, you will lead the design, development, and integration of complex vacuum seal systems for our pulsed magnetic inertial fusion platform. This role focuses on designing robust seals for high‑vacuum, air, and water interfaces exposed to extreme fusion conditions.

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 of vacuum seals 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 for seal validation 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 guide the integration of vacuum seals into the fusion target area
• Document sealing processes, validation data, and lessons learned
• Mentor and support junior engineers on vacuum system design and integration challenges

Qualifications

• Bachelor's or Master's degree in Mechanical, Aerospace, or a related engineering field, or equivalent experience
• 8+ 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 & 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

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.