Firmware Engineer

Mill; San Bruno (CA); On-site; USD 185,000 - 210,000; Full time

Job summary

Mill is a waste prevention technology company transforming food scraps into resources. We seek a Firmware Engineer to design low‑level firmware for our connected product, integrating Wi‑Fi, Bluetooth, and sensor systems. You will collaborate with cloud services, mobile apps, and hardware teams to deliver robust, secure firmware.

The role emphasizes working with MCU platforms, RTOS, and connectivity stacks, ensuring scalable, production‑readiness firmware for large deployments.

Qualifications

• 3+ years of embedded systems experience.
• Strong C programming for embedded environments with memory management and RTOS concepts.
• Hands-on with connectivity modules (Wi‑Fi, Bluetooth) and interfaces (GPIO, I2C, SPI, UART).

Responsibilities

• Design and implement firmware on MCU platforms with wireless connectivity, OTA updates, sensor integration, and data exchange.
• Develop and optimize communication stacks for Wi‑Fi, Bluetooth, and other wireless protocols.
• Integrate firmware with hardware peripherals via GPIO, I2C, SPI, UART.
• Apply robust error handling and performance optimization for reliable connectivity.
• Collaborate with cross‑functional teams to debug, test, and ensure system reliability and security.
• Contribute to production readiness for large‑scale deployment.
• Evaluate code quality to maintain best practices and consistency.

Skills

C programming

Embedded systems

Networking

RTOS (FreeRTOS)

GPIO I2C SPI UART

Education

Bachelor’s degree in Computer Science, Electrical Engineering, or equivalent

Tools

ESP32

Wi-Fi/Bluetooth modules

Git/CI/Build systems

Job description

Mill is a waste prevention technology company reimagining what it means to eliminate waste, starting with food. We build smart systems and infrastructure for homes, businesses, and municipalities that transform food scraps from landfill-bound waste into valuable resources, including chicken feed. Tens of thousands of Mill’s residential food recyclers are already helping households divert millions of pounds of food scraps every year, paving the way for our upcoming launch of Mill Commercial—the industry’s first end-to-end solution for managing, understanding, and preventing food waste in commercial environments (e.g. grocery, restaurants, food services). At Mill, we are passionate about building easy-to-use, beautifully designed technologies that keep food in the food system and out of landfills.

We're seeking a Firmware Engineer to design, develop, and implement low-level firmware for our next‑generation connected product. You'll work closely with cloud services, mobile app, product and hardware teams to integrate Wi‑Fi, Bluetooth, and other connectivity features seamlessly, while actively collaborating and contributing as a key team player.

Key Responsibilities

• Design and implement robust firmware on MCU platforms, ensuring support for wireless connectivity, data upload, OTA updates, sensor integration, and other core functionalities.
• Develop and optimize communication stacks for Wi‑Fi, Bluetooth, and other wireless protocols, ensuring reliable pairing, network configuration, and data exchange.
• Write efficient low‑level code that integrates with hardware peripherals (e.g., RF modules, sensors) using standard interfaces such as GPIO, I2C, SPI, and UART.
• Apply best practices for error handling and performance optimization to support robust connectivity features.
• Work closely with cross‑functional teams to rigorously debug, test, and troubleshoot firmware, ensuring optimal performance, reliability, and security.
• Engage actively with multidisciplinary teams, sharing insights and aligning on system‑level requirements to drive cohesive project success.
• Contribute to the deployment readiness of our systems for large‑scale production.
• Evaluate code from peers to maintain best practices in style, accuracy, and efficiency.

Required Qualifications

• Bachelor’s degree in Computer Science, Electrical Engineering, or equivalent experience, with 3+ years work experience in embedded systems development.
• Deep understanding of computer networking and firmware for data‑intensive applications.
• Strong expertise in C programming for embedded systems, with a solid grasp of memory management and real‑time operating system principles.
• Hands‑on experience with connectivity modules (Wi‑Fi, Bluetooth) and RTOS (FreeRTOS preferred).
• Proficiency in hardware‑software interfacing, including protocols like GPIO, I2C, SPI, and JTAG.
• Proficiency with troubleshooting tools (debuggers, Wireshark) and measurement equipment (multimeters, oscilloscopes, logic analyzers).
• Demonstrated expertise in debugging and rigorous testing to quickly identify and resolve complex issues.
• Familiarity with version control, CI, and build systems.

Preferred Skills

• Experience with ESP32 microcontrollers.
• Working knowledge of cloud computing protocols (e.g., MQTT) and platforms like AWS (AWS CDK is a plus).
• Experience with cellular connectivity.
• Excellent communication and interpersonal skills to foster a collaborative, team‑oriented environment.

The estimated base salary range for this position is $185-$210K which does not include the value of benefits or a potential equity grant. A wide range of factors are considered in making compensation decisions, including but not limited to skill sets, market conditions, experience and training, licensure and certifications, and business and organizational needs.