Critical Loop is an industrial power solutions company that deploys modular battery, generation and software-defined microgrid systems to accelerate grid interconnection.
About Critical Loop Critical Loop is shaping the next generation of energy systems by building the integrated edge grid of the future. Specializing in advanced energy management and battery control systems, Critical Loop empowers businesses and communities to seamlessly unite distributed energy resources for faster, more reliable, and affordable grid access. With deep expertise in grid modernization and a passion for creating resilient, responsive energy solutions, Critical Loop drives innovation at the intersection of technology and energy. TEST ENGINEER - MULTIPLE OPENINGS - ON-SITE IN LONG BEACH, CA The Role We are hiring Test Engineers to build our hardware test capability from the ground up. You will be the owner of our hardware-in-the-loop (HITL) infrastructure, production unit test process, and canary fleet procedures, building and maintaining each as the hardware test pipeline our reliability story is built on. You will design and build the HITL testbeds, stand up the production unit test process, and own the canary fleet procedures that our hardware reliability story is built on. The test outcomes you produce will feed directly back into the hardware we ship to customers. This is a hands-on, on-site role working alongside the Operations and Product Development teams. What You'll Do - Design, build, and maintain hardware-in-the-loop (HITL) testbeds for Critical Loop's product line, starting with the CLB5100 and expanding to the CLB5020 and beyond - Develop and operate production unit test processes and procedures, ensuring issues are caught before units reach customer sites - Stand up and own canary fleet usage processes, tooling, and operational standards - Author and maintain test procedures, documentation, and standards as the source of truth for how Critical Loop validates hardware - Analyze test data and translate findings into actionable feedback that improves the hardware we ship - Lead root cause analysis on hardware failures and edge cases surfaced through testing, and stay with the problem until it is solved - Partner with engineering and field ops to align test infrastructure with deployment realities - Build the test engineering function from nothing and do not wait for process or tooling to exist before creating it Must-Haves - Hands-on experience designing, building, and operating hardware test setups — not only running existing ones - Demonstrated experience authoring test procedures and the operational standards around them with substantive contributions to the build and methodology - Strong root cause analysis skills, with the ability to drive complex hardware issues to ground in systems you own end to end - Willingness to engage with the software side of testing, including reading code, writing scripts, and committing to git repositories - Bachelor's degree in electrical engineering, mechanical engineering, or a related field, or equivalent practical experience - Comfortable operating as the test engineering function for a product line, setting your own priorities and managing your own work without an existing test organization to lean on Nice-to-Haves - Direct experience with hardware-in-the-loop (HITL) testbeds and the trade-offs around fidelity, cost, and maintainability - Experience with data acquisition systems, sensors, DAQs, and logging or telemetry forwarding software - Familiarity with Python, git, and Linux - Background in power electronics or high-voltage systems - Background spanning both R&D and production environments Critical Loop is an equal opportunity employer. We're committed to building a diverse team and creating an inclusive workplace where everyone can thrive. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, veteran status, or any other protected characteristic under applicable law.