Principal Mechanical Engineer
berkshiregrey
Principal Mechanical Engineer
mainspringenergy· Mechanical and Structural Systems
About this role
About Mainspring
Mainspring Energy manufactures and delivers fuel-flexible, low-emissions local power solutions that rapidly add new capacity and deliver reliable, affordable, and sustainable electric power. The company began commercial shipments of its Mainspring Linear Generators in 2020 and today has hundreds of megawatts in advanced development and field operations for leading Fortune 500 companies, data centers, and utilities. Mainspring also partners with global energy leaders including AEP, NextEra Energy Resources, Schneider Electric, and more.
The core values that ground our work, guide our decisions, and connect us together:
Pragmatic Optimism
Excellence without Ego
Proactive Collaboration
About the Role
Mainspring is seeking a Principal Mechanical Engineer to serve as a company-level technical authority in a critical mechanical engineering domain for our Linear Generator platform. In this role, you will shape long-term technical direction, define or strongly influence architecture and design principles, guide high-consequence technical decisions, and help the organization solve problems that are novel, ambiguous, and central to long-term product and business success.
This role is intended for engineers who have already demonstrated broad technical leadership across multiple teams, systems, or major program areas and are now ready to create durable company-level technical leverage. A strong candidate should be able to operate with exceptional autonomy, advise senior leadership, anticipate long-term technical and business risks, and create principles, standards, methods, or decision frameworks that improve how Mainspring approaches major classes of engineering problems.
Candidates who primarily shape technical direction across multiple teams or system areas may be better aligned to a Senior Staff Mechanical Engineer role. Principal-level candidates should bring rare technical judgment in a company-critical domain and demonstrate impact that extends beyond individual projects, teams, or near-term program execution
Frequently Asked Questions
What is the salary for the Principal Mechanical Engineer role at mainspringenergy?
The listed salary for this Principal Mechanical Engineer position at mainspringenergy is USD 210K–247K. This is an Salary role.
Where is the Principal Mechanical Engineer position at mainspringenergy located?
This Principal Mechanical Engineer role at mainspringenergy is based in Menlo Park, CA. The position is listed as on-site or hybrid. Check the full job description or apply directly to confirm the work arrangement.
Is the Principal Mechanical Engineer role at mainspringenergy full-time or part-time?
This is listed as a Salary position. It is posted as a Principal Mechanical Engineer role in the Mechanical and Structural Systems department at mainspringenergy.
Which team or department does the Principal Mechanical Engineer at mainspringenergy belong to?
This Principal Mechanical Engineer position is part of the Mechanical and Structural Systems department at mainspringenergy. See the full job description for more information about the team structure and responsibilities.
How do I apply for the Principal Mechanical Engineer position at mainspringenergy?
Click the "Apply Now" button on this page. You will be redirected to mainspringenergy's official application portal hosted on lever where you can submit your application directly.
When was the Principal Mechanical Engineer job at mainspringenergy posted?
This Principal Mechanical Engineer position at mainspringenergy was posted on Aug 6, 2026. Apply as soon as possible — early applications are often reviewed first.
Principal Mechanical Engineer
mainspringenergy · 💰 USD 210K–247K
You'll be redirected to mainspringenergy's official application page on Lever.