Staff Mechanical Engineer

About the role

Mainspring Energy invites a Staff Mechanical Engineer to take defined ownership over specific mechanical engineering workstreams and moderate-complexity projects that directly support the Linear Generator platform. In this capacity, you will design mechanical hardware components, support analysis and testing efforts, and drive assigned work from concept through validation and release. The role requires pragmatic optimism and excellence without ego as you collaborate across functions to solve challenging mechanical problems. You will exercise proactive collaboration with manufacturing, quality, supply chain, test, and service teams to ensure designs are manufacturable, reliable, and fit for purpose. This position is suited for an engineer who has moved beyond learning fundamentals and is ready to independently own defined-scope mechanical engineering tasks with sound judgment and clear communication. You will identify common risks, make tradeoff decisions, follow through on deliverables, and rely on available support for ambiguity and higher-risk choices. The work demands consistency in applying mechanical fundamentals to deliver tangible progress on Mainspring's commercial energy solutions. This role contributes directly to the company's mission of delivering reliable, affordable, and sustainable electric power through fuel-flexible technology.

Key facts

What you'll do

Define and own moderate-complexity mechanical engineering workstreams and projects for the Linear Generator platform, translating requirements into coherent mechanical designs.

Develop detailed mechanical hardware designs, including parts, assemblies, and mechanisms, while applying analysis and testing to guide design decisions.

Support validation and testing activities, using data to refine designs, resolve issues, and ensure performance against specifications.

Collaborate with cross-functional teams such as engineering, manufacturing, quality, supply chain, test, and service to advance project goals.

Drive assigned work through full release cycles, ensuring deliverables meet standards for documentation, verification, and readiness.

Identify and communicate technical risks, proposing mitigation strategies in coordination with stakeholders.

Apply mechanical fundamentals to solve practical problems related to materials, fabrication, and system integration.

Communicate clearly with both technical and non-technical audiences, maintaining alignment across distributed functions.

Follow through on project commitments, managing tasks and timelines with support available for complex tradeoffs.

Contribute to continuous improvement by learning from test results, manufacturing feedback, and field performance data.

Support the development of tools, fixtures, and processes that improve design efficiency and manufacturability.

Translate business and system requirements into actionable mechanical engineering tasks with clear acceptance criteria.

Work within defined processes to ensure designs comply with relevant standards, safety considerations, and operational requirements.

Support the company's growth by enabling scalable and reliable mechanical solutions for current and future deployments.

Requirements

Demonstrate practical mechanical engineering experience through multiple design, analysis, test, release, or implementation cycles in relevant applications.

Apply sound mechanical fundamentals, including but not limited to mechanics, materials, and dynamics, to solve engineering problems.

Independently own defined-scope engineering work, showing ability to manage ambiguity and execute with minimal supervision.

Identify common risks in mechanical designs and propose appropriate mitigation strategies.

Communicate clearly and effectively with cross-functional teams, using structured problem-solving approaches.

Follow through on deliverables, meeting commitments and maintaining quality in fast-paced, iterative environments.

Work comfortably in collaborative settings, integrating input from manufacturing, quality, supply chain, and service teams.

Adapt to evolving priorities and changing requirements while maintaining focus on project goals and standards.

Nice to have

Experience with fuel-flexible power systems or distributed generation technologies.

Understanding of system-level integration and how mechanical designs interact with electrical and control systems.

Background in data centers, utilities, or large-scale energy infrastructure deployments.

Experience supporting hardware validation, testing, or field operations.

Practical notes

This role is based in Menlo Park, California.

The engagement is salary-based.

Travel, if any, is not specified in the available source information.

Visa sponsorship details are not provided in the available source information.

No specific deadline for applications is included in the available source information.