Senior Firmware Engineer

HLTH is one of the fastest growing brands of 2026, reaching the top 0.1% in hyper-growth of all stores in the Shopify ecosystem and we're just getting started (literally). At HLTH we believe understanding your health should be effortless. Our products turn health monitoring into clear insights anyone can act on.

We are looking for our first in-house Firmware Engineer to join our small but mighty team. This role requires a highly motivated Firmware Engineer with experience in embedded systems and wearable devices to develop our next-generation of connected wearable devices. Our firmware will run on tens of thousands of devices in the field, making reliability, maintainability, and careful engineering critical parts of the role. You will work hands-on with the founders, our BLE engineer, and our biosignal engineer, and remotely with our factories and vendors to bring up boards and ship releases. The initial firmware release will be completed in conjunction with an external agency, which you will lead that initiative and maintain ongoing updates.

• Design, develop, test, and maintain embedded firmware in C on Zephyr / nRF Connect SDK, owning firmware modules and features from design through production.
• Develop and integrate drivers for PPG, 6-axis motion (25–100 Hz), and skin temperature sensors, working with sensor and chipset partners to deliver raw data that meets our quality bar.
• Build reliable sensor acquisition, buffering, and on-device storage pipelines, and hand data cleanly to the Bluetooth layer owned by our BLE engineer.
• Optimize power consumption, memory usage, and overall system performance so every sensor runs within the power budget set by our BLE engineer.
• Build and maintain secure OTA firmware updates with signed images and rollback so a band is never bricked, and own versioning, testing, and releases across thousands of devices.
• Support firmware bring-up, debugging, validation, and production readiness remotely with our factory, including manufacturing test firmware.
• Develop robust error handling, watchdog, crash logging, and recovery mechanisms, and investigate and resolve issues observed on devices in the field.
• Participate in firmware architecture, design, and code reviews, and review our firmware partner's code so HLTH keeps full control of the codebase.
• Write unit, integration, and hardware-level tests, and develop test tools, automation scripts, and diagnostic utilities to improve development efficiency.

• 4+ years of embedded firmware development, including firmware shipped on a battery-powered wearable or sensor device.
• Direct experience developing firmware for consumer health wearables such as smart bands, rings, or watches.
• Strong programming skills in C (C++ a plus) and a strong understanding of ARM Cortex-M microcontrollers, memory management, interrupts, and concurrency.
• Hands-on experience shipping on Nordic nRF with Zephyr RTOS / nRF Connect SDK, including Device Tree, Kconfig, and MCUboot.
• Experience developing drivers for sensors and peripherals over SPI, I²C, UART, GPIO, and ADC, and the ability to read datasheets, register maps, and hardware specifications.
• Shipped secure OTA/DFU firmware updates in a real product, including signed images, secure boot, and rollback.
• Experience bringing up and debugging boards remotely, and coordinating with external firmware vendors and factories.

• Experience with Goodix or similar PPG sensor front ends and high-rate sensor data acquisition (ring buffers, FIFOs, CRC, and data packetization).
• Working knowledge of BLE profiles and wearable communication architectures, enough to hand off cleanly to the BLE layer.
• Experience building test tools and automated testing for firmware releases.
• Python scripting for firmware test tools, plus exposure to firmware CI/CD pipelines and long-duration stress testing.
• Ability to work independently and drive feature ownership, with a product-oriented focus on reliability and user experience.

• Competitive regional salaries
• Fully remote, flexible hours
• Access to custom AI tooling and workflows
• Flat team, direct access to founders
• Unlimited PTO (with a required recharge time)