Senior Firmware Engineer

ABOUT THE ROLE Join the core hardware team of a Y Combinator–backed consumer wearable startup as a Senior Firmware Engineer, helping build the firmware powering a next-generation wearable platform. You'll play a foundational role in defining the firmware architecture and taking a category-defining device from prototype all the way through to mass production. This role sits at the intersection of low-power embedded design, sensor integration, and production engineering — and it matters because the reliability and battery life of the product depend on the work you'll own. You'll be working in-person in New York City alongside a small, fast-moving engineering team. WHAT YOU'LL DO - Architect and develop embedded firmware for battery-powered wearable devices. - Own core systems for low-power wireless connectivity, sensor processing, and data pipelines. - Design and optimize Bluetooth Low Energy (BLE) connectivity for ultra-low-power operation. - Build robust power management systems to maximize battery life. - Develop multi-core embedded data pipelines for real-time sensor acquisition and processing. - Integrate biometric and environmental sensors via SPI, I2C, UART, GPIO, DMA, and interrupts. - Optimize firmware for performance, memory usage, latency, and reliability. - Lead board bring-up, debugging, validation, and manufacturing support. - Collaborate closely with hardware, algorithms, product, and industrial design teams across the full product lifecycle. - Establish firmware best practices, testing frameworks, and CI workflows. WHAT WE'RE LOOKING FOR Required - 6+ years of embedded firmware engineering experience, with a track record of shipping battery-powered consumer electronics or wearables to production. - Deep expertise in Bluetooth Low Energy (BLE) systems and low-power embedded architectures. - Strong proficiency in Embedded C/C++ and RTOS-based systems (e.g., FreeRTOS, Zephyr). - Hands-on experience with ARM Cortex-M microcontrollers and modern debugging tools. - Experience building multi-core embedded data pipelines for real-time sensor acquisition. - Proven power management architecture skills for always-on, low-power embedded systems. - Sensor integration experience using SPI, I2C, UART, GPIO, DMA, and interrupt-driven designs. - Experience with board bring-up, debugging, validation, and manufacturing support. Nice to Have - Background in sensor fusion, signal processing, or biometric sensing. - Experience with embedded platforms such as Nordic, Qualcomm, Ambiq, or STMicroelectronics. - Familiarity with secure bootloaders, OTA firmware updates, and embedded security practices. - Experience building wearable or health-tech devices. - Comfort moving quickly in a fast-paced, collaborative startup environment. COMPENSATION & BENEFITS - Salary: $120,000 – $200,000 per year, depending on experience. - Equity participation typical of an early-stage startup. - Visa sponsorship: Not available at this time. LOCATION This is a full-time, on-site role based in New York City, NY. The team works in person together — remote or fully distributed arrangements are not available for this position.