Director of Mechanical Engineering
Mainspring Energy, Menlo Park, CA, United States
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.
Our Values
Pragmatic Optimism
– Building a new category of world‑class power generation requires 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 individually. 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. Director of Mechanical Engineering
We are seeking a Director of Mechanical Engineering to lead a substantial portion of the team scaling the Linear Generator – a first‑of‑kind distributed power platform that converts a low‑temperature, flameless reaction directly into electricity using high‑frequency linear motion instead of rotating machinery. The system integrates reciprocating pressure‑driven assemblies, air‑spring return chambers, precision alignment systems, and linear electromagnetic machines within a modular 250 kW‑class packaged unit. It operates under cyclic loads, tight sealing constraints, thermal gradients, structural dynamics, and grid‑interactive performance requirements typical of commercial power generation equipment. Reporting to the VP of Mechanical Engineering, this role expands leadership capacity, elevates risk visibility, and enables disciplined scaling of a growing hardware portfolio. You will own ~40‑50% of the mechanical organization’s active projects and lead ~25 direct and indirect reports, with scope expected to grow. Your teams will oversee multiple core subsystems that are tightly coupled and reliability‑critical. Success requires both deep mechanical intuition and strong organizational leadership. You will strengthen technical rigor, improve prioritization across 50+ active efforts, and build execution systems that allow the organization to scale without sacrificing engineering excellence. Core Responsibilities
Leadership of ~25 engineers (direct and indirect), including managers 40‑50% of the mechanical project portfolio Accountability for multiple core subsystems Early identification and mitigation of subsystem and program‑level risks Strong engineering review discipline (FMEA, DVP&R, tolerance analysis, ECO governance) Partnership with Manufacturing and Supplier Quality to support at‑scale production Development of future engineering leaders Qualifications
18+ years delivering complex industrial or energy hardware Experience in high‑volume, at‑scale environments Leadership of 15‑30+ engineers (direct + indirect) Strong judgment around technical and program risk Ability to balance architecture evolution with production realities Management experience required; Director title not mandatory Senior‑level design credibility to lead experienced engineers We are committed to building a diverse, inclusive, flexible, and collaborative environment. If your experience does not meet every posted requirement, we would still love to hear from you. Mainspring can be flexible enough to shift responsibilities for the right person or identify open or upcoming roles that may better fit your 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. 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 plus benefits.
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Pragmatic Optimism
– Building a new category of world‑class power generation requires 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 individually. 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. Director of Mechanical Engineering
We are seeking a Director of Mechanical Engineering to lead a substantial portion of the team scaling the Linear Generator – a first‑of‑kind distributed power platform that converts a low‑temperature, flameless reaction directly into electricity using high‑frequency linear motion instead of rotating machinery. The system integrates reciprocating pressure‑driven assemblies, air‑spring return chambers, precision alignment systems, and linear electromagnetic machines within a modular 250 kW‑class packaged unit. It operates under cyclic loads, tight sealing constraints, thermal gradients, structural dynamics, and grid‑interactive performance requirements typical of commercial power generation equipment. Reporting to the VP of Mechanical Engineering, this role expands leadership capacity, elevates risk visibility, and enables disciplined scaling of a growing hardware portfolio. You will own ~40‑50% of the mechanical organization’s active projects and lead ~25 direct and indirect reports, with scope expected to grow. Your teams will oversee multiple core subsystems that are tightly coupled and reliability‑critical. Success requires both deep mechanical intuition and strong organizational leadership. You will strengthen technical rigor, improve prioritization across 50+ active efforts, and build execution systems that allow the organization to scale without sacrificing engineering excellence. Core Responsibilities
Leadership of ~25 engineers (direct and indirect), including managers 40‑50% of the mechanical project portfolio Accountability for multiple core subsystems Early identification and mitigation of subsystem and program‑level risks Strong engineering review discipline (FMEA, DVP&R, tolerance analysis, ECO governance) Partnership with Manufacturing and Supplier Quality to support at‑scale production Development of future engineering leaders Qualifications
18+ years delivering complex industrial or energy hardware Experience in high‑volume, at‑scale environments Leadership of 15‑30+ engineers (direct + indirect) Strong judgment around technical and program risk Ability to balance architecture evolution with production realities Management experience required; Director title not mandatory Senior‑level design credibility to lead experienced engineers We are committed to building a diverse, inclusive, flexible, and collaborative environment. If your experience does not meet every posted requirement, we would still love to hear from you. Mainspring can be flexible enough to shift responsibilities for the right person or identify open or upcoming roles that may better fit your 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. 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 plus benefits.
#J-18808-Ljbffr