hirly

Mainspring Energy

Director of Mechanical Engineering

Menlo Park, CA

See how you match this job — and similar ones. Free.

Upload your resume and hirly scores it against this role at Mainspring Energy first, then against similar open jobs, and shows where you fit and why.

PDF or DOCX, up to 12MB. No sign-up to see your matches.

Get past the screening software and onto a recruiter's desk

hirly rewrites your resume for this job — matching the keywords and skills in the posting, moving your most relevant experience to the top, and writing a cover letter to fit. About 30 seconds.

  • Keywords matched to this posting
  • Fit score before you apply
  • Cover letter included
Tailor my resume for this job →

Apply from your AI assistant

Connect hirly to Claude and ask it to apply to this job. hirly tailors your resume, fills the employer’s form and asks before sending. ChatGPT: manual setup today.

Some employer sites stop an application at a CAPTCHA or sign-in and hand it back with a link. Applying needs a paid plan. Works with any assistant that supports MCP.

hirly's read of this role

Seniority
Director
Stated salary
$237,000 – $267,000 per year
Country
US
Work mode
On-site / unstated
First seen by hirly
21 Sept 2026

Derived automatically from the posting. Upload your resume above to see how the role scores against it.

the posting

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.

Original posting on Mainspring Energy's site ↗

Listed on hirly, a job board. hirly is not the employer: Mainspring Energy is hiring for this role.

Browse similar roles

Want this one?

Upload your resume and hirly rewrites it for this job and writes the cover letter — in about thirty seconds, before you sign up.

Tailor my resume for this job