Senior NPI Manufacturing Engineer

Mainspring Energy
Mainspring Energy

Other Engineering

Menlo Park, CA, USA

USD 115k-136k / year + Equity

Posted on Mar 13, 2026

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 Energy seeks a Manufacturing Engineer to join our New Product Introduction (NPI) team. This role involves learning about our novel linear motor design and participating in the development of new manufacturing techniques, tooling, and equipment for deployment at our North American production sites. This role will be critical in ensuring the successful manufacturing of high-precision components and assemblies at scale, focusing on quality, efficiency, and cost optimization.

The ideal candidate will be project-oriented, possess experience in designing electromechanical systems and tooling, be adept at working with complex assemblies, and utilize a data-driven approach to problem-solving. Proficiency in 3D CAD software is required to create mechanical part models and assemblies, as well as to generate 2D detailed drawings for fabrication.

This position necessitates a proactive approach and requires collaborative engagement with our Product Design and Test Engineering teams, Supply Chain, Quality, Manufacturing, and Operations team members.

Key responsibilities encompass the design and development of new manufacturing processes, troubleshooting, fine-tuning, validation, and the deployment of processes and tooling into production. Additional responsibilities include drafting tooling and equipment specifications, project management, managing project scope and schedule, developing process control (SPC) and quality plans, writing work instructions, and conducting training. The incumbent must be capable of resolving complex issues as they arise on the production floor while maintaining a strategic view of the overall objective.

What you'll do

  • Create mechanical 3D CAD models and 2D fabrication drawings
  • Lead the design of high-precision fixtures, tools, and equipment for electromechanical assembly and testing
  • Apply DOE, PFMEA, and other industry-standard tools to identify risks and optimize process parameters
  • Execute rapid prototyping, proof-of-concept studies, and process/tooling validation
  • Define process equipment requirements, develop comprehensive RFQs, and lead procurement engineering from specification to sourcing
  • Design actuators, select sensors and pneumatic components, develop machine BOMs, and define COTS part specifications
  • Conduct equipment process capability (Cpk & GR&R) validation tests and publish results
  • Generate equipment documentation, including test plans, operation, troubleshooting, and maintenance manuals
  • Train and hand off equipment to Operations/production staff
  • Participate in failure root cause and corrective action analysis using 8D methodology

What you'll bring

  • Bachelor’s or Master’s degree in Mechanical Engineering, Manufacturing Engineering, Mechatronics, or a related field
  • 5+ years of experience in mechanical or electromechanical equipment design, FAT/SAT process
  • Hands-on experience and ability to supervise mechanical assembly, wiring, plumbing, and light machine shop skills
  • Proficient in 3D CAD design, GD&T, and drafting (Solidworks ideal)
  • Strong analytical and problem-solving skills
  • Excellent communication, collaboration, organizational, and prioritization skills
  • Proficient with Google Apps suite
  • Knowledgeable in process validation testing and statistical tools (JMP or Minitab)
  • Valid passport and ability to travel in North America (10-25% max)
  • Must be available to work daily at the Menlo Park, CA facility

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.

115000 - 136000 USD a year

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 the base salary, Mainspring offers pre-IPO stock options + benefits.