Senior Embedded Systems Engineer (EE/FW)

Simbex is seeking a Senior Embedded Systems Engineer to own the full hardware-firmware stack for a next-generation IoT wearable platform. This is a dual-discipline role: you will independently design and develop embedded hardware circuits and PCBs alongside production-grade Zephyr RTOS firmware — from component selection and schematic capture through board bring-up, sensor integration, and field deployment. The ideal candidate is a hands-on engineer wh o takes end-to-end ownership in building sensor-based hardware and firmware . Essential Functions: Electrical Engineering & Hardware Development Own hardware design from component selection and schematic capture through PCB layout review and design-for-manufacture Lead board bring-up: power sequencing, peripheral initialization, signal integrity verification, and fault isolation Design and characterize low-power analog front-ends and power management subsystems for battery-operated wearables Develop hardware test fixtures and produce electrical characterization reports Firmware Architecture & Development Architect and deliver production Zephyr RTOS firmware on ARM Cortex-M/R targets Author device drivers, BSPs, and devicetree overlays; implement sensor acquisition pipelines for IMU-based impact detection Design low-power state machines and event-driven architectures for wearable operation Set firmware coding standards, CI/CD pipelines, and architecture guidelines for the team IoT & Wireless Connectivity Implement BLE stacks for real-time telemetry and configuration; design OTA update mechanisms via MCUboot Integrate cloud connectivity (MQTT/CoAP) and evaluate edge vs. cloud trade-offs for impact detection Signal Processing & Algorithm Integration Port impact detection algorithms from MATLAB or Python into constrained C/C++ firmware Apply sensor fusion (Madgwick, Mahony, complementary filter) for accurate head kinematics from multi-axis IMU data Optimize DSP routines for speed and memory footprint on resource-constrained targets Testing & Quality Define and execute unit, HIL, and system integration test plans; build automated regression frameworks Maintain design documentation, traceability matrices, and test reports; support compliance activities Required Qualifications: BS or MS in Electrical Engineering, Computer Engineering, Embedded Systems, or related field 7+ years of embedded development experience, including 3+ years on production-shipped products Hands-on EE skills: independently read schematics, perform board bring-up, and debug hardware/firmware interaction Proficiency with bench instrumentation (oscilloscope, logic analyzer, power analyzer) for power characterization and debug Experience selecting microcontrollers, RF SoCs, and sensor ICs (IMU, accelerometer, gyroscope) for product designs Strong C/C++ in bare-metal and RTOS-based embedded contexts Demonstrated Zephyr RTOS experience: devicetree , Kconfig , module system, and west toolchain Experience with ARM Cortex-M SoCs (Nordic nRF52/nRF53, STM32, or similar) and peripherals: SPI, I2C, UART, USB BLE firmware experience and familiarity with OTA update workflows ( MCUboot preferred) Preferr ed Qualifications: Sensor fusion algorithm experience (Madgwick, Mahony) and algorithm porting from MATLAB/Python Exposure to sports biomechanics, head impact research, or wearable athletic sensing Cloud IoT platform experience (AWS IoT Core, Azure IoT Hub) and embedded security (TLS/DTLS, secure elements) Multi-core SoC development (e.g., nRF5340) or experience in a regulated/safety-critical product environment