Senior Firmware EngineerSoftware Engineering * Berkeley, CA On-site

Role Description

We are hiring a Senior Staff Firmware Engineer to lead real‑time control firmware for power conversion and drive development of the battery management and control system for our multi‑day storage battery system. You will define the control architecture, implement embedded C and C++ on production hardware, apply model‑based design and code generation, and drive certification readiness and fleet‑scale reliability. This role sits within Firmware Engineering and partners closely with Software, Power Electronics, Safety, and Manufacturing Test.

• Work with an interdisciplinary group of engineers on the Systems Team to define concepts, down‑select designs, and optimize the new groundbreaking technology.
• Derive software and hardware specifications and design features based on product requirements to meet UL 1998 and UL 5500 standards.
• Translate grid code and safety requirements into testable features and acceptance tests, and author compliance matrices and test plans.
• Define DC/DC operating envelopes with Power Electronics, covering bidirectional control, battery interface dynamics, current limiting, protection coordination, and thermal derate behaviors.
• Own closed‑loop digital control for DC/DC stages, including current, voltage, and power loops, observers, PLL, droop, P/Q and V/f modes, soft start, protections, and derates.
• Architect firmware for safety with clear state machines, fault detection and recovery, black start and islanding detection, restart policies, and strong diagnosability.
• Develop microcontroller firmware for embedded systems, sensors, and power flow control circuitry for our Battery Management System (BMS).
• Contribute to the unit and integration testing suite, and coordinate with the system and test team, to allow continuous delivery of high‑quality firmware.
• Lead SIL and HIL strategy and execution, model plants in MATLAB and Simulink, build automated regressions, correlate HIL to bench and field data, and gate releases on quantitative criteria.
• Drive EMC and pre‑compliance through design reviews, mitigation guidance, and lab testing.
• Adhere to and raise the bar on the firmware engineering processes and best practices.
• Mentor senior engineers, set bars for code quality and design reviews, and improve processes for continuous delivery of high‑quality firmware.
• Support product deployment and field activities, including troubleshooting and debugging firmware in field environments to ensure performance and reliability.

• Master's degree in electrical engineering, computer engineering, or a related field.
• 10 to 15 plus years of firmware experience for embedded and RTOS systems for battery management and/or power electronics.
• Extensive experience using C or C++ for embedded systems in real‑time, multithreaded control applications.
• Strong embedded fundamentals including bare‑metal or RTOS, fixed‑point math, interrupt‑driven control, unit tests, and HIL regressions.
• Expert knowledge of power control algorithms and digital control design for power converters including PWM generation, current and voltage loops, observers, filters, and stability analysis.
• Proficiency in model‑based design and plant modeling using MATLAB or Simulink, PLECS, PSIM, or similar with traceability to production code.
• Knowledge of peripheral communication protocols such as I2C and SPI, and industrial protocols such as Modbus and CAN.
• Electrical engineering depth including reading schematics, troubleshooting hardware interfaces, and working knowledge of gate drivers, sensors, protections, EMC, thermal, and safe bring‑up.
• Lab proficiency using oscilloscopes, power analyzers, electronic loads, and safe high‑power test practices.
• Familiarity with software compliance standards (e.g., MISRA, ISO 26262, CMMI, ASPICE, or UL 1998) is a plus.
• Experience implementing secure bootloaders and OTA updates with signing and encryption is a plus.
• Excellent collaboration strength and technical leadership cross‑functional influence, design reviews, mentoring, and external lab engagement, and written communication skills.
• Preferred familiarity with grid codes and certification workflows for inverter‑based…