Embedded Engineer Jobs in El Monte, CA (NOW HIRING)

Senior Embedded Software Engineer - Battery Management Systems Location: Long Beach, California (On-site) Employment type: Full time Compensation: $155,000-$221,000, plus equity and benefits Position overview Our client is an engineering-led technology company developing advanced embedded systems for demanding, high-reliability environments. They are seeking an experienced battery-management firmware engineer to own the embedded software for a new microcontroller-based battery subsystem. The role spans cell monitoring, communications, control and protection interfaces, state estimation, sequencing, limits, diagnostics, fault handling and integration with power electronics. This is a hands-on individual-contributor position with end-to-end technical ownership, from early requirements and architecture through hardware bring-up, verification, field support and continued improvement. You will work closely with embedded, electrical, power-electronics and test engineers throughout development and integration. Responsibilities Own the battery-management software subsystem from initial requirements and architecture through production-ready implementation and ongoing support. Develop bare-metal and/or RTOS-based firmware for a microcontroller-based battery-management system. Create and maintain MCU board-support packages, low-level drivers and peripheral interfaces. Implement cell-monitoring, communications, control and protection interfaces. Develop battery-management state machines, operating modes, fault handling, safe states and recovery behaviour. Implement state-of-charge and state-of-health estimation functionality. Develop monitoring, balancing, sequencing, limits, thermal supervision, diagnostics and protection logic. Integrate battery-management firmware with power electronics, communications interfaces and higher-level system controls. Design deterministic real-time software under strict latency, jitter, timing, memory and compute constraints. Configure and debug MCU peripherals including timers, ADCs, interrupts, DMA, non-volatile memory and communication interfaces. Bring up new boards in close collaboration with electrical and power-electronics engineers. Read schematics and component documentation, review hardware interfaces and diagnose hardware/software integration issues. Use oscilloscopes, logic analysers, in-circuit debuggers and related laboratory tools to identify root causes. Develop unit, integration, software-in-the-loop, hardware-in-the-loop and fault-injection tests in collaboration with test engineering. Support laboratory and field testing, production testing, failure investigation and corrective improvements. Improve build automation, continuous integration, static analysis, profiling and automated testing. Produce concise engineering documentation, contribute to technical reviews and mentor other engineers while remaining hands-on. Required qualifications Approximately five or more years of relevant embedded-software experience is preferred; demonstrated technical depth and delivery experience are more important than a specific tenure. Deep practical expertise in bare-metal and/or RTOS-based microcontroller development for real hardware systems. Strong proficiency in at least one low-level systems-programming language, such as C or C++. Practical experience developing software for battery-management, energy-storage, power-electronics or a closely related embedded system. Strong understanding of cell monitoring, battery protection, sequencing, limits, diagnostics, fault handling and safe-state design. Experience with battery state estimation, including state of charge and/or state of health. Experience implementing deterministic software under latency, jitter, timing, memory and performance constraints. Strong understanding of timers, interrupts, DMA, concurrency, synchronisation, memory management and low-level peripheral control. Experience bringing up new MCU boards, reading schematics and debugging integrated hardware/software systems. Experience with common embedded communication protocols and bus architectures. Strong laboratory-debugging skills using oscilloscopes, logic analysers, in-circuit debuggers and related equipment. Experience writing maintainable production code, conducting code reviews, developing automated tests, using static analysis and profiling performance. Ability to work independently with incomplete information while collaborating closely across engineering disciplines. Willingness to support field testing when required. US. citizenship and eligibility to obtain and maintain a U.S. security clearance. Desirable experience Safety-critical, mission-critical or other high-reliability embedded products Taking a greenfield battery-management system through design, verification and operational deployment Cell monitoring and balancing State-of-charge and state-of-health estimation Thermal monitoring, charge/discharge limits and fault-state design Power-electronics integration and high-voltage safety concepts Experience across multiple MCU and RTOS platforms Fault injection, HOOTL, SIL, HIL or HITL test environments Robotics, aerospace, automotive, industrial-control, medical, energy or similarly integrated electromechanical systems Keywords: Senior Embedded Software Engineer, Battery Management System, BMS, Embedded C, C++, Bare Metal, RTOS, Microcontrollers, State of Charge, State of Health, Cell Monitoring, Battery Protection, Power Electronics, Board Bring-Up, HIL Testing and High-Reliability Systems