Senior Firmware Engineer

The magic of Ultrahuman’s wearable technology lies deep within its firmware – the code that directly drives our sensors, batteries, and wireless chips, making the difference between a gadget and a life-changing health device. As a Senior Firmware Engineer, you will be a core part of the team that architects and refines this low-level software. Your work will ensure that our ring and other devices operate with exceptional efficiency and accuracy, balancing complex functionality with ultra-low power usage. In Ultrahuman’s culture of deep engineering, you’ll have the opportunity to apply first-principles thinking to every aspect of firmware, from how we sample signals to how we manage memory. If you want to push the boundaries of what’s possible in wearable tech (the way Tesla pushes EV performance or Apple optimizes its custom silicon), this role offers that challenge and excitement.

Responsibilities:

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  Firmware Development: Design, write, and test firmware for Ultrahuman’s wearable devices (such as the Ring AIR and other health monitors). This includes implementing drivers for various sensors (PPG heart rate sensors, accelerometers, temperature sensors, glucose monitors, etc.), managing Bluetooth Low Energy (BLE) communication, and controlling power management features.
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  Performance Optimization: Optimize code for memory footprint and power consumption. Use a first-principles approach to examine each routine – for instance, determine the minimal necessary sampling frequency for a sensor to preserve battery life while maintaining accuracy or craft interrupt-driven processes to put the MCU (microcontroller) to sleep as much as possible without missing critical data.
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  Feature Innovation: Collaborate with product and hardware teams to introduce new on-device features. For example, implement an on-device algorithm for arrhythmia detection using heart rate data or a simple gesture recognition using the ring’s motion sensor. Work on sensor fusion techniques that combine data streams in firmware to send richer information to the app.
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  Testing & Reliability: Develop thorough testing protocols for firmware. This means writing unit tests for your code where applicable (using device simulators or HIL setups) and working with QA to do extensive real-world testing of firmware updates. When issues arise (like a rare device crash or a sensor glitch), dive into debugging – using tools like JTAG debuggers, logic analyzers, or custom logging – to find root causes and fix them.
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  Documentation & Code Quality: Produce clear documentation for firmware architecture, APIs, and usage of hardware peripherals. Maintain high code quality standards through code reviews and adherence to safety practices (especially as our devices may be health-critical, firmware robustness is paramount). Contribute to the continuous improvement of our firmware development process, whether it’s improving the build system, CI for firmware, or introducing new tools for efficiency.

Requirements

• Educational Background: Bachelor’s or Master’s in Electrical/Computer Engineering, Computer Science, or related field. Strong understanding of embedded systems fundamentals.
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  Experience: 5+ years of hands-on experience in firmware or embedded software engineering, ideally with some of that in the wearable, IoT, or medical device space. Proven track record of shipping firmware that runs on commercially released hardware.
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  Programming & Tools: Proficient in C/C++ for embedded systems. Familiarity with ARM Cortex-M microcontrollers (or similar architectures) and RTOSes (FreeRTOS or Zephyr) is highly desirable. Experience with BLE stacks and protocols. Comfortable using version control (git) and typical embedded development tools (compilers, debuggers, oscilloscopes, etc.).
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  Low-Level Mastery: Strong grasp of hardware interfaces and protocols (SPI, I2C, UART, ADC, PWM, etc.). Ability to read schematics/datasheets to understand how to interface with new components. Experience optimizing for low-power operation (sleep modes, interrupts, efficient use of peripherals).
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  Problem-solving: Excellent debugging skills. Experience in diagnosing issues such as memory leaks, concurrency problems, or odd hardware behaviour. You should approach debugging analytically, forming hypotheses and testing them systematically.

Preferred Experience:

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  Wearables/Medical Devices: Direct experience working on a health or fitness wearable, or any product that had to collect biometric data. Familiarity with regulatory standards like FDA software guidance or ISO 13485 (for medical device software) can be a bonus, as it shows a mindset for safety and rigour.
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  Algorithm Implementation: Experience implementing signal processing or simple machine learning algorithms on embedded devices (e.g., heart rate algorithms, activity classification, filtering techniques) to process data before sending it to the cloud.
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  Secure Firmware Practices: Knowledge of secure bootloaders, OTA firmware update systems, and general cybersecurity practices for embedded devices (since protecting user data and device integrity is critical).
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  Passion for First-Principles: A demonstrable passion for tinkering at the low level. Perhaps you have personal projects like building your own IoT devices, contributing to open-source firmware projects, or writing blogs about creative embedded solutions – indicating that you love diving deep and innovating from scratch.