Firmware Engineer

The role

This engineer will design, build, debug, secure, and optimize embedded software for next generation access control, intercom, IoT, wireless, and connected hardware products. The role involves working across bare-metal, RTOS, and embedded Linux platforms.

What you will do

• Design, write, debug, and maintain firmware across bare-metal, RTOS/Zephyr, and embedded Linux platforms.
• Build reliable low-level firmware in C/C++ for microcontrollers, peripherals, sensors, and communication interfaces.
• Develop architectures optimized for timing, memory, latency, power, boot time, and long-term reliability.
• Own firmware from board bring-up and prototype development through production release and post-launch support.
• Work close to hardware including registers, buses, interrupts, ADCs, and power rails.
• Read schematics and collaborate with electrical and mechanical engineers.
• Diagnose multi-domain failures using oscilloscopes, logic analyzers, debuggers, and multimeters.
• Implement secure boot, bootloaders, certificate signing, and secure OTA updates.
• Develop and debug firmware for I2C, SPI, UART, GPIO, ADC, PWM, RS-485, USB, Ethernet, BLE, Wi-Fi, and cellular systems.
• Use AI models and engineering tools to accelerate code development, debugging, and test creation.

Required qualifications

• 5+ years of hands-on embedded firmware development experience
• Strong firmware development skills in C/C++
• Hands-on experience with bare-metal microcontroller firmware, RTOS-based systems, and embedded Linux
• Strong understanding of microcontroller architecture, interrupts, timers, DMA, memory maps, bootloaders, watchdogs, peripheral drivers, low-power modes, and low-level register programming
• Deep practical understanding of electronics hardware, including digital and analog domains, power regulation, ADCs, signal conditioning, filtering, impedance, noise, grounding, and signal integrity
• Experience debugging real hardware using oscilloscopes, logic analyzers, debuggers, programmers, multimeters, and other lab equipment
• Experience with embedded communication interfaces such as I2C, SPI, UART, CAN, RS-485, USB, BLE, Wi-Fi, Ethernet, and cellular-connected systems
• Experience with secure boot, firmware signing, certificate signing, device identity, key provisioning, encrypted communications, and secure OTA update mechanisms
• Experience developing firmware for connected IoT products
• Familiarity with higher-level communication patterns and protocols such as MQTT, REST, WebSockets, TLS, device-to-cloud APIs, and remote device management
• Ability to read schematics, understand PCB layouts, and reason about hardware behavior
• Ability to troubleshoot multi-domain failures involving hardware, firmware, networking, environment, manufacturing, and customer installation factors

Nice to have

• 8+ years is preferred for senior-level candidates
• Experience with Zephyr is strongly preferred
• Ideally including products deployed in commercial, industrial, access control, building systems, consumer electronics, or field-installed environments

Benefits

• Comprehensive Medical, Dental and Vision plans (ButterflyMX covers 80% of the cost) starting day 1
• 401(k) plan with a match
• 10 paid holidays, 20 vacation days, 5 sick days, 3 floating holidays
• Basic Life and Accidental Death and Dismemberment Insurance (ButterflyMX covers 100% of the cost)
• Short and Long Term Disability (ButterflyMX covers 100% of the cost)
• Paid Family Leave
• Employee Assistance Program
• Quarterly self-care stipends
• Access to optional benefits including pre-tax flexible healthcare spending accounts (FSA and HSA), Dependent Care FSA, and Commuter Benefits
• Optional Supplemental Life, AD&D, Hospital Indemnity, Legal, Accident, Critical Illness, Pet, and Personal Liability Insurance

Before you apply

• You must have the authorization to work in the US to become an employee

About the company

ButterflyMX is on a mission to empower people to automate property access, operations, and security from a single platform. As a distributed, primarily remote workforce, they are driven by a shared commitment to excellence and innovation.