Senior Manufacturing Engineer
Mainspring Energy
Menlo Park, CA, USA
USD 115k-136k / year + Equity
Posted on Feb 4, 2026
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 an innovative and highly skilled Manufacturing Engineer to lead the design, development, and implementation of assembly tooling, material handling systems, and scalable production processes for a groundbreaking large electromechanical machine.
In this role, you will play a critical role in translating product designs into manufacturable, high-precision, and robust components and assemblies at scale. You will work closely with Mechanical Design engineers to drive DFM/DFX initiatives, process error-proofing, and tooling robustness, ensuring efficiency, repeatability, and quality across our production lines.
The ideal candidate will have a strong background in precision fixture design, material handling solutions , overhead lift assist systems, and MES systems. Experience in precision measurement and laser-based assembly processes is a significant advantage. Additionally, this role requires end-to-end ownership, including sourcing, assembly, commissioning, and installation of designed systems.
Join our team if you are ready to bring your expertise to the forefront of manufacturing technology, contributing to the success of our linear generator startup.
Responsibilities
- Lead the design of high-precision fixtures, tools, and equipment for electromechanical assembly and testing.
- Develop material handling solutions, overhead lift assist systems, and custom conveyors, Joining technologies and Torque/Angle control Nutrunners.
- Implement precision measuring systems and laser alignment processes for high-tolerance assembly.
- Ensure all tooling and equipment meet rigorous quality and performance standards.
- Manage end-to-end project execution, from concept through installation and commissioning.
- Collaborate with cross-functional teams, including R&D, operations, and procurement, to align manufacturing solutions with product requirements.
- Layout planning for future factory design initiatives and collect and document product and process requirements to feed equipment and tooling design and also define the process readiness for automation introduction.
- Oversee the manufacturing and assembly of designed tooling and equipment, ensuring timelines and quality standards are met.
- Contribute to new product development and collaborate with design engineers, offering expertise in manufacturability (DFM/DFX) and cost effectiveness of new mechanical components designs. .
- Utilize DOE, PFMEA, 8D and other industry-standard tools and techniques to actively identify and address risks and optimize process parameters
- Assess the sustainability of a fabrication technology for a given part design, plan validation experiments to demonstrate initial feasibility as well as manufacturing capabilities. Analyze the result and provide technical recommendations.
Qualifications
- Bachelor’s or Master’s degree in Mechanical Engineering, Manufacturing Engineering, or a related field.
- 5+ years of experience in manufacturing engineering, with a focus on tooling and automation.
- Proficiency in CAD software (e.g., SolidWorks, CATIA, or AutoCAD) for tooling and fixture design.
- Strong analytical and problem-solving skills.
- Hands-on experience and ability to supervise mechanical assembly, wiring, plumbing, and light machine shop skills.
- Familiarity with precision measuring systems, laser alignment tools, and GD&T principles.
- Finite Element Analysis (FEA) capability is a plus.
- Willing and able to travel internationally up to 15%
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.
115000 - 136000 USD 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.