Senior Sales Engineer

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.

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

Job Overview

The Senior Sales Engineer reports to the Senior Sales Engineering Manager and serves as a senior technical contributor within the sales cycle for solution architecture, estimating, and system integration strategy. As a member of the Sales Engineering team (a subset of Project Delivery), this role exercises independent technical judgment to develop cost-optimized, execution-ready solutions aligned with Mainspring’s linear generator capabilities. The Senior Sales Engineer is accountable for architectural integrity, commercial rigor, and seamless transition from concept through execution.

Responsibilities

• Develop system architecture, preliminary designs, and cost estimates from concept through execution handoff
• Articulate and support sound technical approaches, ensuring appropriate design integration and trade-off evaluation
• Produce complete, accurate, and timely proposal packages across multiple concurrent projects
• Build well-supported cost estimates, proactively communicate risks, and incorporate market inputs into pricing assumptions
• Support customer meetings, site walks, and solution presentations as the technical subject matter expert
• Communicate technical concepts in clear, structured, and solution-oriented formats across customer and internal stakeholders
• Collaborate with Engineering, Product, Controls, Commissioning, and Project Management to support technical feasibility and execution alignment
• Contribute to peer design reviews to share technical perspective and strengthen overall solution quality

Qualifications

• Bachelor’s degree in Electrical, Mechanical, Systems, or Energy Engineering
• 7+ years of experience in sales engineering, applications engineering, front-end engineering development (FEED) or cost estimating within electrical power systems or related industries
• Experience in distributed energy, solar, batteries, fuel cells, microgrids, or related technologies preferred
• Familiarity with electrical power systems, three-phase inverters, protection relays, and the physics of grid integration
• Strong understanding of standard electrical drawings such as wiring diagrams, electrical schematics, and one-lines
• Ownership mentality: proactive in identifying risks and comfortable advocating for the resources needed to solve them
• Ability to travel nationally (~25%)

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.

This position is remote and eligible for a 25% annual bonus . 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 and benefits.