Senior Staff Mechanical Engineer - Electromechanical

Company Overview

Mainspring Energy is revolutionizing power generation with the world’s most flexible and adaptable local power generation technology, the Mainspring Linear Generator. Commercial, industrial, and utility leaders are choosing Mainspring over traditional options like engines, turbines, and fuel cells to quickly and reliably deliver local power for EV charging, commercial facilities, data centers, and grid-scale operations. The Mainspring Linear Generator is fuel flexible, ramps up and down to meet demand, and utilizes a flameless reaction with near-zero NOx emissions.

Backed by top-tier investors including Khosla Ventures, Bill Gates, American Electric Power, Lightrock, and General Cayalyst Mainspring designs, manufactures and delivers its products to customers across the U.S. today, and we’re quickly scaling for international expansion.

Inspired by our vision of the affordable, reliable, net-zero carbon grid, Mainspring is rapidly expanding within the $816B global electricity equipment market, and we’re hiring the best talent to meet growing customer demand around the globe. We welcome a broad range of backgrounds, experiences, and talents to bring fresh perspectives and ongoing innovation to our customers.

We are looking to build relationships with people who share our values:

Pragmatic Optimism.

Building a new category of world-class power generation requires the optimism of ambition and creativity, balanced with practicality to solve problems efficiently. The challenges that arise are opportunities for growth.

Excellence without Ego.

We bring expertise and commitment to creating the best customer experience, from sales to deployment and service, just as we apply deep technical rigor to building and delivering world-class products. We strive for excellence and behave as leaders with the humility to acknowledge our challenges, both collectively and as individual contributors.

Proactive Collaboration.

The integration and cross-disciplinary nature of Mainspring’s business requires intentionally seeking out others who bring different skills, perspectives, and priorities. Our culture of inclusion and respect extends beyond our team to interactions with our partners and customers.

More information can be found at

www.mainspringenergy.com

Job Overview

Mainspring is seeking Sr. Staff Mechanical Engineers with a focus on designing electrical enclosures and cables while improving functionality and system-level performance. This role will involve not only owning engineering development projects but also taking a leadership role in guiding technical decisions and influencing the design process across teams. You will work with cross-functional teams to ensure that key electrical and mechanical subsystems meet challenging technical requirements from concept through manufacturing launch. You will directly manage engineers, providing leadership while ensuring that all team members work towards a cohesive project goal. Ideal candidates will have a strong combination of technical expertise, leadership abilities, and the drive to solve complex problems in a collaborative environment.

Core responsibilities

- Lead ideation and design reviews to develop innovative solutions that enhance performance and reduce cost of the Linear Generator and its electrical subsystems

- Own the structure, layout, optimization, prototyping, testing, and deployment of electrical enclosures and harnesses

- Partner with Electrical, Reliability, Test, NPI, Manufacturing, and supplier teams to define design direction, validate solutions, and meet project milestones

- Oversee execution by setting requirements and coordinating across disciplines to maintain cohesive technical direction

- Manage and mentor engineers, guiding technical decisions, setting priorities, and supporting professional growth

- Proactively balance timelines, resources, and risks to ensure consistent delivery on key engineering initiatives

Qualifications

- Degree: BS or MS in Mechanical, Electrical, or related engineering field with 11 years of industry experience

- Proven ownership of electrical enclosure and cable designs, with experience influencing cross-functional teams

- Deep expertise in sheet metal, mechanical–electrical integration, and design for manufacturability

- Strong foundation in electrical principles, thermal modeling, and system-level design

- Proficient in SolidWorks and PDM; experience with CFD/FEA tools (e.g., Ansys) is a plus

- Demonstrated ability to make technical trade-offs, guide design direction, and deliver complex systems

- Passion for mentoring engineers and advancing high-impact, low-carbon energy technologies

Does your experience not meet all of our posted requirements? Studies have shown that some people are less likely to apply to positions unless they meet every listed requirement. At Mainspring, we are committed to building a diverse, inclusive, flexible, and collaborative environment, so if you want to help us transition the world to clean and affordable electricity, and don’t meet all posted requirements for a particular role, we’d still love to hear from you. Mainspring can sometimes be flexible enough to shift responsibilities for the right person, or otherwise identify open or upcoming roles that may better fit your professional background.

In more traditional words, Mainspring Energy, Inc is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, or protected veteran status and will not be discriminated against on the basis of disability.

This compensation and benefits information is based on Mainspring Energy's estimate as of the date of publication and may be modified in the future. We generally do not negotiate on salary once we have made an offer. The level of pay within the range will depend on a variety of job-related factors that may include location, relevant prior experience and/or education, or particular skills and expertise. New hires joining the company tend to be paid within the starting base pay range noted above, with opportunities to increase pay over time based on development of additional skills, competencies, and company-specific knowledge.

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.

This position is 

onsite

at our Menlo Park HQ. The salary will be adjusted to reflect local market conditions based on employee location as well as the experience of the employee. Along with the base salary, Mainspring offers pre-IPO stock options + benefits.