Senior Field Service Technician; Indiana

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 generator is fuel‑flexible, ramps up and down to meet demand, and utilizes a flame‑less 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. and is scaling for international expansion.

Inspired by our vision of an affordable, reliable, net‑zero carbon grid, Mainspring is rapidly expanding within the $816B global electricity equipment market, hiring the best talent to meet growing customer demand worldwide.

• Pragmatic Optimism. Building a new category of world‑class power generation requires ambition and creativity balanced with practicality to solve problems efficiently.
• Excellence without Ego. We focus on deep technical rigor and the best customer experience, behaving as leaders with humility.
• Proactive Collaboration. The integration and cross‑disciplinary nature of Mainspring’s business demands intentional collaboration across teams and partners.

More information can be found at

We are searching for highly motivated, mechanically inclined individuals to join our growing Field Service team. You will play a direct role in completing planned and reactive service operations on our generators, maintaining system uptime and performance for deployed units on customer sites in a specific region. Training will occur at our headquarters in Menlo Park, CA before assignment to a service region that requires travel.

Opportunities for growth within Mainspring and full benefits—including vacation and sick time, 401(k), and pre‑IPO stock options—are available.

• Mechanically repair and maintain components and assemblies that make up our generators in accordance with procedures and build checklists to meet customer requirements.
• Collaborate with engineers to fix, repair, and redesign components and assemblies.
• Conduct mechanical inspections of deployed units, documenting condition information for use in debugging or troubleshooting.
• Be available to work rotational on‑call shifts, as per the written schedule, to provide optimal service and support for customers.

• Minimum of 5 years of experience with mechanical assembly and/or repair; experience with automotive, aviation, or heavy equipment (e.g., HVAC, elevators, or industrial equipment) is a plus.
• Experience with precision measuring down to .001”, using micrometers, bore gauges, gauge blocks, and familiarity with torque wrenches and documentation of repairs performed.
• Ability to stand for long periods, lift up to 50 lbs., and wear required PPE.
• Knowledge of basic tools such as torque wrenches and torque specifications.
• Experience following written and verbal work instructions while on‑site.
• Excellent communication skills; proficiency with Google Workspace is a plus.
• A proven track record of working well with others as part of a dynamic team.
• Self‑motivated, safety‑oriented, and quick learner.
• Valid driver’s license required;
  Class C commercial driver’s license preferred.

If your experience does not meet all posted requirements, we still welcome your application. Mainspring is committed to building a diverse, inclusive, flexible, and collaborative environment and may adjust responsibilities for the right candidate or identify suitable roles.

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, protected veteran status, or disability.

This position is onsite in Valparaiso, IN. The salary will be adjusted to reflect local market conditions and the employee’s experience. Along with the base salary, Mainspring offers pre‑IPO stock options and benefits, including vacation and sick time, 401(k), and other benefits.

This compensation estimate may be modified in the future. Mainspring generally does not negotiate salary once an offer has been made. Pay will depend on factors such as location, experience, or particular skills.

We may use artificial intelligence tools to support the hiring process, but final hiring decisions are made by humans. For more information about how your data is processed, please contact us.