SlipstreamJobs tracks this role from the company's public career site. Apply directly on the employer's site.
Salary: USD 150,000 - 190,000 / annual
ButterflyMX is seeking an exceptional Firmware Engineer to design, build, debug, secure, and optimize embedded software powering next-generation access control, intercom, IoT, wireless, and connected hardware products. The company's platform automates property access, operations, and security across 20,000+ multifamily, commercial, gated communities, and student-housing properties worldwide.
This role sits at the critical intersection of electronics, embedded systems, product reliability, device security, and customer experience. You will work across multiple embedded environments including bare-metal microcontroller firmware, RTOS-based systems (particularly Zephyr), and embedded Linux platforms. This is a hands-on position requiring strong firmware development skills, deep hardware intuition, and practical embedded systems judgment.
Key responsibilities include:
- Develop production-ready embedded firmware in C/C++ across bare-metal, RTOS/Zephyr, and embedded Linux platforms, owning firmware from board bring-up through EVT/DVT/PVT, production release, and post-launch support.
- Work close to hardware including registers, buses, interrupts, ADCs, power rails, signal integrity, timing, and analog/digital interactions; read schematics, understand PCB layouts, and collaborate with electrical and mechanical engineers.
- Diagnose multi-domain failures using oscilloscopes, logic analyzers, debuggers, and other lab tools; build firmware resilient to power instability, brownouts, signal noise, temperature extremes, and communication faults.
- Implement secure boot, bootloaders, chain of trust, signed firmware, certificate signing, key provisioning, device identity, and secure OTA updates with rollback protection.
- Develop and debug firmware for I2C, SPI, UART, GPIO, ADC, PWM, RS-485, USB, Ethernet, BLE, Wi-Fi, and cellular-connected systems; implement reliable protocol handlers and robust error handling.
- Design firmware with observability, diagnostics, manufacturability, and field support in mind; support built-in self-test, production test firmware, manufacturing diagnostics, and automated validation.
- Use AI tools responsibly to accelerate development while maintaining independent validation and engineering judgment.
- Approach problems holistically across electronics, firmware, mechanical constraints, manufacturing variation, and customer impact; prototype quickly, test carefully, and iterate toward robust designs.
Requirements:
- 5+ years of hands-on embedded firmware development experience (8+ years preferred for senior-level candidates).
- Strong firmware development skills in C/C++ for resource-constrained embedded systems.
- Hands-on experience with bare-metal microcontroller firmware, RTOS-based systems, and embedded Linux; Zephyr experience strongly preferred.
- 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 lab equipment.
- Experience with embedded communication interfaces: 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, ideally in commercial, industrial, access control, building systems, consumer electronics, or field-installed environments.
- Familiarity with higher-level communication patterns: MQTT, REST, WebSockets, TLS, device-to-cloud APIs, and remote device management.
- Ability to read schematics, understand PCB layouts, reason about hardware behavior, and collaborate with electrical engineers.
- Ability to troubleshoot multi-domain failures involving hardware, firmware, networking, environment, manufacturing, and customer installation factors.
- Experience with Git, CI/CD, automated testing, static analysis, issue tracking, release management, and disciplined software development practices.
- Strong documentation skills including design notes, ICDs, state diagrams, test plans, debug guides, release notes, and technical decision records.
- Strong initiative, tenacity, lateral thinking, and comfort in fast-moving product development environments.
- AI-forward mindset with engineering maturity to use AI tools as accelerants, not substitutes for deep technical understanding.
