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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, 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
We are seeking a highly capable Manufacturing Engineer with a strong mechanical engineering foundation to bridge the gap between product design and scalable production.
In this role, you will partner closely with Mechanical Design Engineering to ensure our products are not only functional, but manufacturable, scalable, and robust at volume. You will play a critical role in shaping design decisions early-driving DFM/DFX, tolerance strategies, and assembly error-proofing into the product architecture.
This is not a downstream role. You will actively challenge and influence design concepts, ensuring they are suitable for high-volume production-not just prototype success.
The ideal candidate combines strong mechanical design fundamentals with hands-on manufacturing experience and thrives in collaborative, fast-paced environments.
What you'll do
Design for Manufacturability (Core Focus): Partner with Mechanical Design Engineers to translate product concepts into manufacturable, scalable solutions

• Drive DFM/DFX initiatives, including tolerance stack-ups (GD&T), datum strategy, and assembly sequencing
• Convert assembly process learnings (error-proofing, access, ergonomics) into clear design requirements
• Actively influence and challenge product design decisions using first-principles engineering and manufacturing constraints
• Contribute to design decisions with understanding of stress, interfaces, and system integration

Assembly and Equipment design: Design and develop fixtures, jigs, and assembly equipment with a focus on precision, repeatability, and cost

• Perform tolerance analysis and support detailed 2D drawing creation for fabrication
• Support early validation through prototyping, testing, and iteration
• Select and integrate actuators, sensors, and standard components; define functional sequences for automation
• Emphasize simple, robust solutions using off-the-shelf components where possible

Manufacturing Scale-Up:

• Own the transition of assembly processes from prototype builds to scalable production systems
• Plan and validate production processes using PFMEA, DOE, and capability studies (Cpk, GR&R)
• Collaborate cross-functionally with Quality, Supply Chain, and Operations to move from prototype to volume production
• Support factory layout, line design, capacity planning, and continuous improvement efforts

What you'll bring
Education and work experience:

• Bachelor's or Master's degree in Mechanical Engineering or related field
• 5+ years of experience in mechanical design, manufacturing engineering, or a hybrid role

Strong foundation in:

• Proficiency in CAD tools (e.g., SolidWorks, CATIA)
• GD&T and tolerance stack-up analysis
• 2D drawing creation for manufacturing
• Datum strategy and precision assembly
• Demonstrated experience influencing product design for manufacturability
• Experience designing assembly processes and scaling from prototype to production

Familiarity with:

• PFMEA, 8D, DOE
• Process capability (Cpk), GR&R
• Assembly technologies (fastening, machining, laser metrology)
• Willingness to travel internationally up to 15%

What Sets You Apart

• Ability to challenge design decisions with data and first-principles thinking
• Strong intuition for "what will break at scale" vs. what works in prototype
• Hands-on mindset-you're comfortable on the floor validating your ideas
• Bias for simple, cost-effective solutions over over-engineering

$116,000 - $136,000 a year
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.
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.