Embedded BLE Firmware Engineer – Biometric Wearable Prototype (Dog Health Collar)

PetTagz is a U.S.-based pet health technology startup developing a smart health monitoring collar for dogs. We are building a proof-of-concept prototype using off-the-shelf chipsets and need an experienced embedded firmware engineer to bring the sensor stack to life. The Hardware Stack • Nordic nRF52840 (BLE) • Analog Devices / Maxim MAX32664 biometric sensor hub • MAX30101 PPG / pulse oximetry sensor • 3-axis accelerometer (IMU) • Temperature sensor (thermistor) What We Need • Firmware to initialize and read from the MAX32664 sensor hub (HR, HRV, SpO₂) • IMU and temperature sensor integration • BLE data transmission via Nordic SDK (nRF Connect SDK preferred) • Clean, documented code we own outright (full IP transfer required) • Basic data output to a phone or PC for prototype validation — no polished app needed This Is NOT • A consumer app project • A smartwatch or fitness band clone • A production-ready product This is a bench prototype to validate sensor signal through dog fur. Rough and functional beats pretty and slow. You Should Have • Shipped at least one BLE wearable firmware project • Hands-on experience with Nordic nRF52 SDK • Experience with Maxim/ADI biometric sensor chips (MAX30101, MAX32664, or similar PPG sensors strongly preferred) • Ability to work independently with minimal hand-holding • English communication sufficient for async updates To Apply Please describe a specific BLE wearable firmware project you have shipped, what chipset you used, and what biometric sensors were involved. Generic applications will not be considered.