Staff Software Engineer: Embedded Power Systems & Functional Safety

OUR MISSION   SPAN IS ENABLING ELECTRIFICATION FOR ALL ⚡ WE ARE A MISSION-DRIVEN COMPANY DESIGNING, BUILDING, AND DEPLOYING PRODUCTS THAT ELECTRIFY THE BUILT ENVIRONMENT, REDUCE CARBON EMISSIONS, AND SLOW THE EFFECTS OF CLIMATE CHANGE. - Decarbonization is the process to reduce or remove greenhouse gas emissions, especially carbon dioxide, from entering our atmosphere. - Electrification is the process of replacing fossil fuel appliances that run on gas or oil with all-electric upgrades for a cleaner way to power our lives. AT SPAN, WE BELIEVE IN: - Enabling homes and vehicles powered by clean energy - Making electrification upgrades possible - Building more resilient homes with reliable backup - Designing a flexible and distributed electrical grid THE ROLE SPAN's Device Software team is responsible for all of the software that is physically embodied in our hardware products. The SPAN Panel is a safety-critical electrical device at the heart of the home energy system; our software directly governs how power flows, how faults are detected and responded to, and how the system remains safe under all conditions. We seek collaborative, top-tier engineers who excel at solving complex problems alongside their peers. Our culture is rooted in strong support and a deep trust in our team's capabilities. Engineers work directly with the broader software, product, and hardware teams to ensure the right things get built at the right time. RESPONSIBILITIES As a Staff Engineer on the Device Software team you will own the design and implementation of the control algorithms and functional safety architecture that govern how the SPAN Panel manages electrical power. This means designing real-time control systems and algorithms, owning the full functional safety lifecycle for software components (including hazard analysis, FTA, SW-FMEA, and certification artifacts), and setting the engineering standard for how we build safe, reliable power control software. You will drive safety-critical features from conception through implementation and certification, working independently and influencing the broader team and organization. Representative Projects - Designing and implementing control algorithms for power management (including load shedding logic, relay actuation sequencing, and fault response state machines) running on MCUs in an RTOS environment, working with system architects to define requirements and validate behavior across operating conditions. - Owning the functional safety software lifecycle for new features: authoring hazard analyses and software FMEAs, designing safety mechanisms and diagnostics into firmware, and producing the documentation and evidence packages required for UL 1998, UL 60730, and UL 3141 certification. - Developing fault injection frameworks and Hardware In the Loop test methodologies that validate safety mechanisms across bench and system-level test environments, and evangelizing functional safety best practices across the Device Software team and partner teams. ABOUT YOU  Required Qualifications We are seeking a Staff Embedded engineer with: - Deep knowledge of electrical power systems, including power conversion, load control, energy metering, the behavior of switching systems, and the ability to translate that domain knowledge into correct, safe embedded software - Experience designing and implementing real-time control algorithms on microcontrollers, including PID controllers, state machine-based control systems, and timing-critical software in RTOS environments - Hands-on functional safety process experience with UL 1998, UL 60730, and/or UL 3141 (or an equivalent standard such as IEC 61508 or ISO 26262), including safety analysis techniques such as FTA and SW-FMEA - 7 or more years of experience writing embedded software for hardware devices in C++ or object-oriented C on microcontrollers - Strong fundamentals in modern software design: object-oriented design, manual memory management, and real-time constraints - Exceptional interpersonal communication and collaboration skills: great at building trust, driving decisions to resolution, and influencing cross-functional teams - Track record of taking ownership over projects end-to-end and mentoring others through design and code review - Able to evaluate requirements and translate them into engineering tasks through implementation and testing Bonus Qualifications We do not expect any engineer to have all skills, but we do want you to be excited to learn and grow. Every Device Software Engineer is free to roam up and down our device software stack, so any combination of the following skills is welcome but can be developed on the job. - Proficiency using AI tools for software architecture, design, implementation, and testing - Experience with the STM32 microcontroller family or other ARM Cortex-M processors - Experience with high-voltage or energy storage systems or solar inverters - Experience with standard electrical communication interfaces such as UART, I2C, USB, Ethernet, Modbus, or CAN - Hands-on debugging experience with JTAG debuggers and benchtop test equipment - Experience working in a multidisciplinary environment alongside electrical and mechanical engineering teams - Experience with the V-model of software development with strict requirements on documentation and requirements traceability LIFE AT SPAN Headquartered in San Francisco’s vibrant SoMa neighborhood, we are an eclectic group of creative thinkers who value open communication, teamwork, and a ‘make it happen’ approach to addressing complex challenges.  SPAN embraces diversity and equal opportunity in a serious way. We are committed to building a team that represents a variety of backgrounds, perspectives, and skills.  We’re hiring talented individuals who are driven by success and are passionate about shaping the future of renewable energy. If that sounds like you, we’d love for you to consider joining the rapidly growing team at SPAN. The Perks: ⚡ Competitive compensation + equity grants at a well-funded, venture-backed company ⚡ Comprehensive benefits: 100% employee premiums for base plans on medical, dental, vision with options for additional coverage.  Parental leave up to twenty four (24)  weeks depending on eligibility ⚡ Comfortable, sunny office space located near BART and Caltrain public transit ⚡ Strong focus on team building and company culture: Employee Resource Groups, monthly social events, SPANcakes recognition breakfast, lunch, and learns ⚡ Flexible hours, one holiday per month, and flexible time off   Interested in joining our team? Apply today and we’ll be in touch with the next steps!