Senior Software Engineer in Test

Company Overview

Mainspring Energy is revolutionizing power generation with the world’s most flexible and adaptable local power generation technology, the Mainspring Linear Generator. The system is fuel‑flexible, ramps quickly to meet demand, and uses a flameless reaction with near‑zero NOx emissions. Supported by top‑tier investors such as Khosla Ventures, Bill Gates, American Electric Power, Lightrock, and General Catalyst, Mainspring designs, manufactures, and delivers products across the U.S. and is expanding internationally.

We are looking for an SDET Engineer to build and run automated testing systems that ensure quality across our highly integrated hardware‑software platform. The role involves collaborating with developers, designing test frameworks, and creating validation workflows for complex integrations.

• Architect automation: design, scale, and maintain robust test frameworks and CI/CD integrations.
• System validation: create workflows to validate complex hardware/software integrations and resolve system‑level bottlenecks.
• Root cause analysis: lead failure analysis and risk mitigation to ensure test stability and environment reliability.
• Strategic coverage: drive risk‑based testing strategies to ensure comprehensive coverage of all critical‑path functionalities.

• Experience &
  
  Education:
  
  Bachelor’s degree in Computer Science or a related field with 6+ years of professional experience, or a Master’s degree with 5+ years in an SDET or Software Engineering role.
• Engineering mindset: self‑directed contributor who treats test infrastructure as a first‑class product and thrives on architecting scalable, automated systems.
• Strategic test design: proven track record of leading complex automation projects from design to implementation, with the ability to perform deep‑dive manual exploratory testing and technical test‑case design.
• Technical versatility: strong hands‑on experience developing in Python and C++, with flexibility to navigate diverse codebases.
• AI workflow ownership: proficiency in leveraging AI coding assistants to boost productivity while exercising professional judgment to ensure system integrity and long‑term maintainability.

This position is onsite at our Menlo Park HQ. Compensation is based on local market conditions and experience, and includes pre‑IPO stock options and benefits. Salary ranges are specified in the posting and may be adjusted based on experience.

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.