Director of Mechanical Engineering

About Mainspring Mainspring Energy manufactures and delivers fuel-flexible, low-emissions local power solutions that rapidly add new capacity and deliver reliable, affordable, and sustainable electric power. The company began commercial shipments of its Mainspring Linear Generators in 2020 and today has hundreds of megawatts in advanced development and field operations for leading Fortune 500 companies, data centers, and utilities. Mainspring also partners with global energy leaders including AEP, NextEra Energy Resources, Schneider Electric, and more. The core values that ground our work, guide our decisions, and connect us together: Pragmatic Optimism Excellence without Ego Proactive Collaboration Director of Mechanical Engineering This is not a pure people-management role. We are looking for a hands-on mechanical engineering leader who has built real hardware, moved fast in imperfect environments, and developed the judgment to recognize technical risk before it becomes a field or manufacturing problem. You should be comfortable leading managers and senior engineers, but also capable of diving into a design review, asking the question that changes the direction of a project, and helping the team make a high-quality decision under uncertainty. The ideal candidate has experience in a startup or high-growth hardware environment where process was incomplete, ownership was still being defined, and the product had to mature while the company was scaling. You may have helped take a product from early development into production, or you may have led major subsystems through repeated design, test, manufacturing, reliability, and field-learning cycles. You know that process matters, but you also know how to build just enough process to improve execution without slowing down creative engineering. Reporting to the VP of Mechanical Engineering, you will lead multiple subsystem-focused teams, develop managers and technical leaders, raise the technical bar, and help the organization scale from heroic execution toward disciplined, repeatable product development.