Senior Reaction Controls Engineer

Mainspring Energy
Mainspring Energy

Software Engineering

Menlo Park, CA, USA

USD 134k-159k / year + Equity

Posted on Sep 18, 2026

Job Overview

    Do you love thermodynamics and dynamic system control? Have you thought about thermodynamic cycles as both continuous and discrete dynamic systems? As other industries convert their thermodynamic machines to electromagnetic machines and electrify their platforms, would you like to help generate that clean electricity?

    Linear generators are a new platform that take advantage of mechanically unconstrained piston motion to cleanly and efficiently oxidize a variety of environmentally friendly fuels with disparate properties (like biogas, hydrogen, and ammonia). The linear generator reaction is close to an ideal Otto cycle, so knowledge and intuition of engine control, thermodynamics, and reaction kinetics are applicable here.

    Mainspring has a high-impact opportunity for a Senior Controls Engineer on our reaction control team to help optimize the system performance by incorporating physics-based models with modern control algorithms to improve reliability, prolong service intervals, and increase power and efficiency.

Responsibilities

  • Implement models, algorithms, and continuous-integration (MIL, SIL, PIL) tests in C++

  • Develop novel fuel, air, compression ratio, and cooling automation and control strategies to improve performance, reliability, and expand the capabilities of the generator to address customer needs

  • Design, execute, and analyze experiments using Python on virtual or real generators to realize the impact of your work on real generators

  • Collaborate with other controls engineers on designs and architectures

  • Debug sensors, actuators, and subsystems for noise and disturbances and assist in calibration, verification, and validation. Communicate algorithms with block-diagrams, pseudo-code, code, etc.

  • Analyze complex thermodynamic-mechatronic systems with experimental data and create representative plant models

  • Support reliability and manufacturing testing of systems under control

  • Analyze data to assess performance capabilities and inform requirements and design decisions

  • Support fleet generator operation to enhance reliability and performance

Qualifications

  • Driven and self-directed enthusiastic contributor

  • Excellent communicator with demonstrated collaboration across multidisciplinary teams

  • Multiple years of experience designing, implementing, and testing algorithms in thermodynamic machines - experience with engines is a plus

  • BS + 5 years relevant experience, MS + 3 years, or Ph.D. in mechanical engineering or related degree

134000 - 159000 USD a year

This is a hybrid position (onsite + remote) at our Menlo Park HQ. It will require you to be onsite as required to perform testing, troubleshooting, manufacturing support, etc. 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.