---
title: 'Staff Mechanical Engineer – Continuous Improvement for Mechanical Design & Quality Control at Mainspring Energy'
canonical: 'https://feeny.ai/job/staff-mechanical-engineer-continuous-improvement-for-mechanical-design-quality-w6caf0yd4q63'
type: 'job'
last_seen: '2026-10-25'
---

# Staff Mechanical Engineer – Continuous Improvement for Mechanical Design & Quality Control at Mainspring Energy

- **Company:** Mainspring Energy
- **Location:** Monterrey, Mexico
- **Compensation:** $55k–$83k
- **Work type:** onsite
- **Posted:** 2026-10-20
- **Last confirmed live:** 2026-10-25
- **Apply:** https://jobs.lever.co/mainspringenergy/17b26119-0e65-4a77-b6e2-d05b6a377f75

## Job description

## 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

Do you have a knack for design of complex mechanical systems? Have you ever invented a tool or changed a process just to make routine installation or service faster and easier? If you're driven by solving real-world design challenges, and working with state of the art mechanical power generation equipment, then this role is built for you.

Mainspring Energy is seeking a Mechanical Sustaining Engineer with a focus on design to lead product improvement efforts across our field and production systems. You will work embedded on site at a contract manufacturer to address design and manufacturing issues at their root. You will support manufacturing with a hands-on approach to solve complex dynamic mechanical problems working directly with the product to take measurements, perform testing, and support pilot efforts to develop rework/retrofit processes.  You will redesign critical components for durability and ease of service, and integrate your findings back into the development process to ensure the long-term reliability and manufacturability of our products.

Core Responsibilities

- Lead the root cause analysis of mechanical failures using data from diagnostics, hands-on testing, and fundamental analysis of bolted joints or material fatigue life

- Redesign or re-engineer components, fasteners, or assemblies to eliminate failures, reduce costs, or improve serviceability

- Coordinate design engineering, manufacturing, and quality teams to ensure that changes are thoroughly tested and validated with short feedback cycles

- Collaborate with NPI, manufacturing quality, and supply chain teams to ensure solutions are optimized for production, vendor capabilities, and field service

- Predict and prevent failure modes by applying a deep understanding of mechanical system interactions, tolerance stack-ups, and real-world use conditions

- Implement feedback loops from field issues into design standards and engineering processes to continuously improve product quality and reduce recurrence

- Manage internal improvement systems that embed learnings into manufacturing process flow and future design development efforts

- Support the development of service tooling, testing fixtures, or diagnostic aids as needed for improved deployment and serviceability

- Travel to HQ in Menlo Park, CA required once per quarter

## Qualifications

- BS or MS in Mechanical Engineering or a similar technical field, minimum BS + 11 years mechanical design experience

- Hands-on experience with mechanical design, including analysis of bolted joints, stress analysis, and structural integrity

- Hands on experience with component and system level testing including measurement techniques and data analysis

- Proven ability to use data-driven root cause analysis to solve complex, cross-functional design issues.

- Experience addressing and resolving field and production issues

- Knowledge of DFM/DFA principles and quality system tools (PFMEA, 8D, CAPA, etc.)

- Deep understanding of tolerance stack-ups and the use of CMMs in inspection processes

- Familiar with manufacturing processes including tube swaging, crimping, potting, stamping, sheet metal, hydroforming, welding, machining, and fabrication

- Proficient in SolidWorks or a comparable CAD package; PDM experience preferred

- Experience with structural FEA and/or is a plus

- A passion for building robust, field-ready solutions with high reliability and serviceability

Why Join Us?

- Directly influence the reliability and field performance of mission-critical mechanical systems

- Collaborate with top-tier engineering teams in a fast-paced and supportive environment

- Be part of an innovation-driven company working on impactful technologies

- Competitive compensation and a full benefits package

- Opportunities for technical leadership and long-term growth

Join Our Mission

We’re committed to building a diverse and inclusive team and welcome candidates from all backgrounds. Even if you don’t meet every requirement, if this role resonates with your skills and passions, we encourage you to apply.

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.

## About Mainspring Energy

## Company Overview
- **One-liner**: Mainspring Energy designs and manufactures fuel-flexible linear generators that provide low-emission, dispatchable onsite power for utilities, data centers, and industrial customers.
- **Entity Type**: Private (Series F)
- **Headquarters**: Menlo Park, California, United States
- **Founded**: 2010
- **Founders**: Shannon Miller

## Core Business
- Primary industry: Electric Power Generation
- Target customers: B2B – utilities, data center developers, enterprise, industrial
- Mission statement: "Redefining how local power is delivered to capacity constrained companies and communities" – enabling clean, reliable, and fuel-flexible power.

## Products & Services
- **[Linear Generator (LGen)]**: A flameless, fuel-flexible generator that converts gaseous fuels (natural gas, biogas, hydrogen, propane) into electricity with near-zero NOx emissions. Modular (0.25 MW per unit), fast-ramping (0-100% dispatchable), 46% electrical efficiency (LHV). Standardized 2.5 MW configuration (10 units). Suitable for grid-parallel or grid-independent operation, microgrids, and balancing renewables.

## Market Standing
- **Valuation/Market Cap**: Not disclosed (private company)
- **Key Metrics**: Annual revenue $117M (latest fiscal year); total funding $813M; 407 employees
- **Notable Investors/Partners**: General Catalyst (led Series F, 2025, $258M), Lightrock (led Series E, 2022, $140M), BloombergNEF (grant), and others.
- **Growth Signals**: Powering the largest U.S. EV truck charging depot; >1 GW of capacity trusted by Fortune 500 companies and utilities; headcount growing +3.4% YoY; job postings up +121.4% YoY (62 active openings); recently expanded into data center market.

## Competitive Advantages
- **Fuel Flexibility**: Single generator can seamlessly switch between natural gas, RNG, hydrogen, and propane without hardware retrofits.
- **Near-Zero Emissions**: <1.5 ppm NOx (0.05 lb/MWh) – meets stringent air quality standards.
- **Dispatchability**: 0-100% load following, grid-independent operation, capable of firming renewables.
- **Low Maintenance**: Only two moving parts, no oil changes, modular design reduces downtime.
- **High Efficiency**: 46% electrical efficiency (LHV) across all scales.
- **Fast Deployment**: Factory-built, skid-mounted units enable rapid installation.

## Strategic Focus
- Scaling manufacturing and deployment to meet growing demand from data centers and utilities.
- Advancing hydrogen and biogas compatibility to support long-term decarbonization.
- Expanding standardized 2.5 MW configurations to lower installed cost and accelerate timelines.
- Building a diverse, cross-disciplinary team to drive innovation in power generation.

## Why Work Here
- Culture of inclusion, respect, and collaboration across engineering, operations, and field teams.
- Emphasis on growth: "We invest in your growth because progress requires people who keep getting better."
- Hybrid/Remote options: headquarters in Menlo Park, manufacturing facilities, and remote field service roles.
- Active hiring across engineering (mechanical, electrical, software), operations, supply chain, and field service.
- Competitive salary ranges (e.g., Engineer ~$107k, Controls Engineer ~$109k, Manufacturing Engineer ~$91k) plus benefits.
- Diverse talent origins from Tesla, Stanford, Apple, SunPower, and other top clean energy companies.

## Sources
1. [mainspringenergy.com/company](https://www.mainspringenergy.com/company)
2. [mainspringenergy.com/careers](https://www.mainspringenergy.com/careers)
3. [jobs.lever.co/mainspringenergy](https://jobs.lever.co/mainspringenergy)
4. [linkedin.com/company/mainspringenergy](https://www.linkedin.com/company/mainspringenergy)
5. [mainspringenergy.com/product](https://www.mainspringenergy.com/product)

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