Senior Field Service Technician (Stockton, CA or Tracy, CA)

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. and is scaling for international expansion.

More information can be found at

We are searching for highly motivated, mechanically inclined individuals to join our growing Field Service team. The role involves completing planned and reactive service operations on our generators, maintaining system uptime, availability, and performance for deployed units on customer sites in a specific region. You will receive training at our headquarters in Menlo Park, CA, and will be assigned to a particular service region, requiring travel.

The position offers full benefits, including vacation and sick time, 401K, pre‑IPO stock options, and ample growth opportunities within Mainspring.

• Mechanically repair and perform maintenance on components and assemblies that make up our generators, following 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 and document condition information for troubleshooting.
• Be available to work rotational on‑call shifts as per the written schedule to provide optimal service and support for our customers.

• Minimum of 5 years of experience with mechanical assembly and/or repair. Experience with automotive, aviation, and/or heavy equipment (e.g., HVAC, elevators/lifts, or industrial equipment) assembly a plus.
• Experience with precision measuring, down to .001”, using micrometers, bore gauges, gauge blocks, etc., 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 how to use and maintain basic tools, such as torque wrenches and torque specifications.
• Experience following written and verbal work instructions while on‑site.
• Excellent communication skills;
  Google Workspace knowledge is a plus.
• Proven track record of working well with others as part of a dynamic team.
• Self‑motivated, safety‑oriented, and able to learn quickly.
• Valid driver’s license required;
  Class A commercial driver’s license preferred.

We welcome applicants who may not meet every requirement. Mainspring is committed to building a diverse, inclusive, flexible, and collaborative environment and may consider flexible role adjustments for the right candidate.

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 compensation and benefits information is an estimate as of the date of publication and may be modified in the future. Pay is based on location, experience, and skills, with opportunities for pay increases over time.

We may use AI tools to support parts of the hiring process, such as reviewing applications and identifying inconsistencies. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are made by humans.

Location:

This position is onsite in Stockton, CA or Tracy, CA. The hourly rate will be adjusted to reflect local market conditions based on employee location and experience. Along with base hourly pay, Mainspring offers pre‑IPO stock options, benefits, and bonuses.