Mainspring Energy

R&D Test Engineer

Mainspring Energy · Menlo Park, CA
Menlo Park, CA $108K–$123K Posted 2026-08-21
Salary
$108K–$123K
Type
Full-time
Experience
3+ yr

Mainspring is seeking an open-minded, curious, and highly motivated R&D Test Engineer who likes to solve challenging cross-functional problems in both a research and production environment. In this role, you will design and execute tests on the Linear Generator, focusing on new electrical and software changes that improve product capabilities and performance.You will lead critical sub-system and system-level development and validation tests on new releases of our product and gain exposure to the entire system, including electrical and mechanical components, software, and controls. The breadth of this role is perfect for an engineer or researcher who wants to use their advanced experimental and analytical skills in a fast-paced product development environment.
•

Perform hands on work and work directly with technicians to troubleshoot, retrofit, and operate our Linear Generator test units

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Collaborate with engineering teams to steer R&D projects by designing and executing experiments that inform product design

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Analyze data, generate reports and communicate results with engineering teams to facilitate learnings and design releases

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Manage test priorities on a daily basis to meet higher level deadlines with a focus on throughput and completing high value studies

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Develop & improve processes and infrastructure to support testing on our next generation products
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Master’s degree in electrical engineering, mechanical engineering, physics, or equivalent with 3+ years of applicable experience

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Experience designing and executing tests in an industrial or academic environment, specifically involving instrumentation and data analysis

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Successful communicator, with a collaborative mindset, who will interface across a range of teams and personalities

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Proficiency in programming with Python/ MatLab/ C++ (at least one)

•

Strong organizational and project management skills
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 company equity through Restricted Stock Units (RSUs) + benefits.

PythonC++
$110K — 10th pctl $270K — 90th pctl
This role’s midpoint $116K vs. market median $180K for Engineering roles
-35%
below median
Based on 10,000+ Engineering roles with disclosed salary ranges tracked on NewJob.
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