Senior Staff Mechanical Engineer - Electromechanical

Mainspring Energy; Menlo Park (CA); On-site; USD 150,000 - 190,000; Full time

Benefits offered by this job

Pre-IPO stock options

Comprehensive benefits package

Job summary

A leading energy technology firm is seeking a Sr. Staff Mechanical Engineer in Menlo Park. The role focuses on designing electrical enclosures and cables, involving cross-functional collaboration to ensure successful product delivery. Ideal candidates have extensive experience (11+ years) in electrical design and mentoring, along with strong proficiency in SolidWorks and related tools. Join us to advance clean and reliable energy solutions while enjoying competitive compensation and benefits, including stock options.

Qualifications

• 11 years of industry experience in engineering.
• Proven ownership of electrical enclosure and cable designs.
• Deep expertise in sheet metal and thermal modeling.
• Strong foundation in electrical principles, thermal modeling, and system-level design.
• 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.

Responsibilities

• Lead ideation and design reviews for the Linear Generator.
• Own structure and layout of electrical enclosures and harnesses.
• Manage and mentor engineers in technical decisions.
• 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.

Skills

Electrical enclosure design

Mechanical-electrical integration

Design for manufacturability

SolidWorks proficiency

Mentorship

Education

BS or MS in Mechanical, Electrical or related engineering field

Tools

SolidWorks

CFD/FEA tools (e.g., Ansys)

Ansys CFD/FEA

Job description

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 Catalyst, 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. We welcome a broad range of backgrounds, experiences, and talents to bring fresh perspectives and ongoing innovation to our customers.

Values

• Pragmatic Optimism. Building a new category of world‑class power generation requires 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, and apply deep technical rigor to building products. We strive for excellence and behave as leaders with humility to acknowledge our challenges.
• Proactive Collaboration. The integration and cross‑disciplinary nature of Mainspring’s business requires seeking others with different skills, perspectives, and priorities. Our culture of inclusion and respect extends beyond the team to interactions with partners and customers.

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 owning engineering development projects, 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. Directly manage engineers, providing leadership while ensuring that all team members work toward a cohesive project goal.

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.

Additional Information

Does your experience not meet all of our posted requirements? At Mainspring, we are committed to building a diverse, inclusive, flexible, and collaborative environment. If you want to help us transition the world to clean and affordable electricity but do not meet all posted requirements, we’d still love to hear from you. Mainspring can sometimes be flexible enough to shift responsibilities for the right person or identify a suitable role.

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, protected veteran status, and disability.

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.

Location: Onsite at our Menlo Park HQ. The salary will be adjusted to reflect local market conditions based on employee location as well as experience. In addition to base salary, Mainspring offers pre‑IPO stock options and benefits.