Firmware Developer

About the role

You will design, develop, test, and optimize production‑ready firmware for a highly constrained, battery‑powered BLE wearable device. The role focuses on the next‑generation smart ring that tracks health and fitness metrics.

Key responsibilities

• Develop embedded firmware in C for the health and fitness tracking ring.
• Integrate and manage physiological and motion sensors.
• Build pipelines for sensor sampling, synchronization, filtering, calibration, and data storage.
• Implement algorithms for heart rate, HRV, activity, steps, sleep, recovery, and temperature trends.
• Develop and optimize BLE communication, GATT services, and secure synchronization with mobile applications.
• Optimize firmware for ultra‑low power consumption, limited memory, thermal constraints, and long battery life.
• Implement battery monitoring, charging control, sleep states, wake‑up behavior, and overall power‑management logic.
• Create secure bootloader and over‑the‑air firmware update functionality.
• Develop manufacturing test, calibration, diagnostic, and device‑logging features.
• Investigate field issues and improve firmware reliability, accuracy, and performance.
• Write automated tests and maintain clear technical documentation.

Required profile

• Excellent knowledge of the C language, including pointers, memory management, bitwise operations, data structures, and resource‑constrained programming.
• Experience with ARM Cortex‑M microcontrollers and resource‑constrained embedded systems.
• Practical knowledge of bare‑metal development and/or embedded real‑time operating systems.
• Experience with Bluetooth Low Energy, GATT profiles, pairing, and device communication.
• Strong understanding of embedded interfaces such as I²C, SPI, UART, GPIO, ADC, interrupts, and timers.
• Experience integrating sensors and working with hardware datasheets and reference designs.
• Knowledge of low‑power firmware architecture and battery‑powered device optimization.
• Proficiency with Git, structured development workflows, and automated testing.
• Strong problem‑solving, communication, and technical documentation skills.

Required skills

• C programming
• ARM Cortex‑M microcontrollers
• Bare‑metal development
• Embedded real‑time operating systems
• Bluetooth Low Energy (BLE)
• GATT profile implementation
• I²C, SPI, UART, GPIO, ADC interfaces
• Interrupts and timers
• Sensor integration
• Low‑power firmware design
• Git version control
• Automated testing

What we offer

• Opportunity to build a next‑generation wearable product from an early stage.
• Solve challenging problems at the intersection of embedded systems, sensor technology, health, and industrial design.
• Direct influence on product architecture and user experience.
• Work with a multidisciplinary team developing globally relevant smart‑ring technology.