Senior Mechanical Engineer - Electromechanical

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

Job Overview

Mainspring is seeking Senior Mechanical Design Engineers with a focus on designing electrical enclosures and cables while improving functionality and system-level performance. In this role, you will lead projects from setting requirements, designing, conducting cross functional reviews, coordinating testing and release to ensure that key electrical subsystems meet challenging technical requirements with a potential for direct reports. Ideal candidates will have a strong combination of technical expertise and the drive to solve complex problems in a collaborative environment.

Core Responsibilities

• Involved in brainstorming and technical review sessions to develop innovative solutions that enhance the performance and cost-efficiency of the Linear Generator and electrical subsystems
• Ownership of design, optimization, and execution of electrical hardware, balancing cost reduction, safety improvements, and system-level reliability
• Collaborate with reliability and test teams to validate systems and components, ensuring fast iteration cycles and incorporating feedback to drive the next-generation deployment of the Linear Generator
• Collaborate cross-functionally with electrical engineering, manufacturing engineering, NPI, and external suppliers to deploy new designs into production, ensuring all systems meet the necessary performance and manufacturability requirements
• Development of electrical hardware, including requirements development, prototyping, testing, iteration, and tooling, ensuring project milestones are met and resources are allocated effectively

Qualifications

• Degree: BS or MS in Mechanical Engineering or a similar engineering field from an accredited institution. Experience and degree will determine the level, with the following minimum requirements: Senior: BS + 5 years or MS + 4 years
• Proven experience taking ownership of electrical enclosure and/or cable design, from initial design to launch
• Strong expertise in sheet metal design for medium-volume production, electrical component specification, mechanical design for electrical systems, and design-for-manufacturability challenges
• A solid understanding of electrical engineering principles and thermal modeling, and the ability to integrate them effectively into larger system designs
• Extensive experience in SolidWorks and PDM (or a similar CAD version control system). Experience with CFD, FEA, and programs like SolidWorks Flow Simulation or Ansys is a plus
• Demonstrated ability to manage complex technical decisions, influence the direction of designs, and coordinate with teams to achieve successful outcomes
• Passion for creating innovative and cost-effective solutions to enable the large-scale deployment of zero-carbon energy technologies

Before you apply, a quick note on your resume

We care about the substance of your work and want to make sure we learn as much as we can about your design experience. To help us evaluate your experience accurately, please ensure your resume includes:

• What you actually built or worked on — name the real product, subsystem, or hardware (not just "components" or "systems"). "Redesigned the bracket mounting the compressor to reduce vibration failures" tells us far more than "designed mechanical components."
• What you personally did, separate from what your team did. If you contributed to a group project, tell us your specific role and contribution.
• The engineering fundamentals you applied — tie your skills (CAD, FEA, GD&T, thermal/fluid analysis, testing, etc.) to the actual problem you used them on, rather than listing them as standalone skills.
• What happened as a result — did it pass validation/testing, resolve a failure, ship to production, and if so, at what volume or scale (prototype quantity, low-rate production, high-volume manufacturing)? This helps us understand whether your experience is with one-off/prototype hardware or product that shipped at scale.

One more thing: please don't feel obligated to keep your resume to one page. If accurately describing your relevant projects and contributions takes more space, that's completely fine — we'd rather see the detail than have you compress or omit meaningful work to fit a page limit.

Thank You!

Does your experience not meet all of our posted requirements? Studies have shown that some people are less likely to apply to positions unless they meet every listed requirement. At Mainspring, we are committed to building a diverse, inclusive, flexible, and collaborative environment, so if you want to help us transition the world to clean and affordable electricity, and don’t meet all posted requirements for a particular role, we’d still love to hear from you. Mainspring can sometimes be flexible enough to shift responsibilities for the right person, or otherwise identify open or upcoming roles that may better fit your professional background.

In more traditional words, 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, or protected veteran status and will not be discriminated against on the basis of disability.

This compensation and benefits information is based on Mainspring Energy's estimate as of the date of publication and may be modified in the future. We generally do not negotiate on salary once we have made an offer. The level of pay within the range will depend on a variety of job-related factors that may include location, relevant prior experience and/or education, or particular skills and expertise. New hires joining the company tend to be paid within the starting base pay range noted above, with opportunities to increase pay over time based on development of additional skills, competencies, and company-specific knowledge.

This position is onsite at our Menlo Park HQ. The salary will be adjusted to reflect local market conditions based on employee location as well as the experience of the employee. Along with base salary, Mainspring offers pre-IPO company equity through Restricted Stock Units (RSUs) + benefits.