Test Software Engineer

Please note that we are unable to provide visa sponsorship for this position.

Proper Voltage is unlocking the next generation of battery technology across robotics, data centers, and defense.

We're building intelligent battery systems that make advanced chemistries (sodium-ion, lithium-titanate, lithium-silicon) work in products that were never designed for them. Humanoid robots can upgrade power systems without redesigning their entire platform. Data centers get safer, cheaper backup power. Drones and autonomous vehicles get higher energy density without lengthy integration cycles.

If you want to work on hard engineering problems that matter this is the place.

We are looking for a Software Test Engineer who is passionate about building reliable, intuitive software tools that help engineers validate and ship hardware. In this role, you will design and develop the test software—both desktop and web-based applications—used by our test engineering team to verify battery management system (BMS) hardware and firmware. You’ll work at the intersection of software and embedded systems, communicating with BMS modules over a variety of hardware interfaces and translating complex test requirements into clean, usable tools.

This is a hands‑on individual contributor role within a fast-moving, multi-disciplinary engineering team.

• Design, develop, and maintain test applications (desktop and web-based) used by test engineers to validate BMS hardware and firmware.
• Build intuitive user interfaces that enable test engineers to efficiently configure and execute test sequences, monitor real‑time data, and review results.
• Implement communication with embedded systems over UART, SPI, I2C, CAN bus, USB, and Ethernet.
• Develop automated test sequences for production validation, design verification, and regression testing of BMS modules.
• Interface with bench instrumentation—programmable power supplies, electronic loads, DAQ hardware, and meters—via SCPI, VISA, or vendor APIs.
• Build data logging, visualization, and reporting capabilities to support test analysis and traceability.
• Collaborate with firmware and hardware engineers to define test protocols covering protection algorithms, cell balancing, state‑of‑charge estimation, and fault detection.
• Maintain version‑controlled repositories with proper documentation, release management, and software quality practices.
• Support manufacturing and quality teams with test fixture software, calibration utilities, and production tooling.
• Contribute to safety compliance testing workflows aligned with UL 1973 and UL 9540 requirements.
• Ability to either work in person at our Carlsbad, CA office or travel there as needed with a demonstrated track record of highly efficient, collaborative remote work.

• B.S. or M.S. in Computer Science, Computer Engineering, Electrical Engineering, or related field.
• 3+ years of experience developing test software or test automation for hardware or embedded products.
• Demonstrated experience building desktop applications (e.g., WPF, Qt, Electron) and/or web applications (React, Angular, Vue, or similar frameworks).
• Hands‑on experience with embedded communication protocols: UART/serial, SPI, I2C, CAN bus.
• Experience interfacing with test and measurement equipment (oscilloscopes, DMMs, power supplies, electronic loads).
• Strong understanding of UI/UX design principles for engineering tools.
• Proficiency with version control (Git) and modern software development practices.
• Ability to read and interpret hardware schematics and datasheets.
• Effective communication skills across various levels of the organization.
• Proven ability to multitask and thrive in a fast‑paced startup environment, with minimal supervision.

• Experience with battery management systems, power electronics, or energy storage products.
• Knowledge of safety and compliance standards for battery systems (UL 1973, UL 9540, IEC 62619).
• Experience with CI/CD pipelines for test software deployment and release automation.
• Familiarity with real‑time data visualization and charting libraries.
• Understanding of signal conditioning, ADC sampling, and precision measurement concepts.

• NI/LabVIEW, Test Stand, or similar test execution frameworks.
• Database design for test data storage and retrieval (SQL, time‑series databases).
• High‑voltage lab environments and associated safety practices.
• Using Python for scripting/data analysis and C/C++ or C# for application development.

Salary range: $120,000 – $155,000 depending on experience and qualifications.

Equity options as part of the compensation package.

Generous paid time off and paid holidays (PTO) policy.

Ready to build the tools that test the future of energy? Let’s talk.