End of Line Technician

Mainspring Energy

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 is rapidly scaling for international expansion.

Inspired by our vision of an affordable, reliable, net‑zero carbon grid, Mainspring is rapidly expanding within the $816 B 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.

Mainspring’s core values:

• Pragmatic Optimism — Building a new category of world‑class power generation requires optimism, ambition, and creativity balanced with practicality to solve problems efficiently.
• Excellence without Ego — We bring expertise and commitment to creating the best customer experience from sales to deployment and service, while applying deep technical rigor.
• Proactive Collaboration — The integration and cross‑disciplinary nature of our business requires us to deliberately seek out others who bring different skills, perspectives, and priorities.

More information can be found at

Mainspring is seeking a motivated and technically skilled End of Line Technician to join our growing Product Testing team. This role is ideal for individuals who thrive in a fast‑paced, hands‑on environment, enjoy mechanical and electromechanical work, and are energized by troubleshooting, testing, and continuous improvement.

As an End of Line Technician, you will play a critical role in the assembly, testing, validation, and occasional field deployment of our next‑generation linear generator technology. You will perform mechanical and electronics assembly, diagnostics, retrofits, functional testing, core validation, emissions testing, and electronics box (eBox) testing, primarily in‑house, with limited field work to support on‑site testing or retrofit activities.

• Collaborate – Partner with cross‑functional build and test teams in a dynamic, fast‑paced production and test environment, and provide support for limited on‑site field activities.
• Mechanical & Electronics Assembly – Assemble mechanical and electromechanical generator components and sub‑assemblies following established procedures, identifying opportunities for process improvements.
• Troubleshoot, Repair & Retrofit – Diagnose and repair mechanical systems and electronic control/power electronics boxes, perform in‑house and field retrofits as needed, and implement design updates with engineers.
• Testing & Validation – Execute comprehensive testing, including core validation, emissions testing, eBox testing, and general generator system functional testing across lab, production, and limited field environments.
• Inspect & Document – Perform thorough inspections, document test results, failures, retrofit actions, and corrective measures, providing actionable feedback to the engineering team.
• Continuous Improvement – Contribute to process improvements focused on safety, throughput, retrofit efficiency, and operational effectiveness in a high‑tempo environment.

• Minimum 3 years of hands‑on mechanical assembly and/or repair experience; experience in fast‑paced manufacturing, automotive, power generation, or heavy equipment environments is a plus.
• Experience with electronics diagnostics, troubleshooting, and retrofit implementation, including control boxes, sensors, wiring harnesses, and connectors.
• Knowledge of…