Manufacturing Engineer - DFM

Mainspring Energy•Menlo Park, CA

3d•$101,000 - $115,000•Onsite

About The Position

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. 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.

Requirements

Bachelor’s or Master’s degree in Mechanical Engineering or related field
3–6 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%

Nice To Haves

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

Responsibilities

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