Principal Firmware Engineer

Fellow•San Francisco, CA

4d•$225,000 - $250,000•Onsite

About The Position

Fellow is seeking a Principal Firmware Engineer to be a hands-on technical leader for their connected products. This role involves defining and evolving firmware and system architecture, developing production embedded software, and ensuring reliable integration across hardware, device UX, connectivity, mobile applications, and cloud services. The position is based in San Francisco, CA, and requires an in-office presence. The ideal candidate will have expert-level embedded engineering fundamentals and experience owning production firmware from architecture and development through OTA delivery and field reliability. This is an opportunity to own the full firmware and connected-systems stack for physical products. The role requires developing, reviewing, and debugging production embedded software, acting as the connective tissue between various product components. The candidate should possess strong technical judgment, a high engineering bar, and operational instincts for shipping reliable, secure systems. They should be able to drive technical decisions independently while remaining agile and pragmatic, and champion AI-assisted engineering tools. This is a hands-on role where the engineer will set architectural direction and also be involved in building, shipping, and debugging. Key responsibilities include owning firmware and connected-system architecture, defining interfaces, engineering standards, and technical roadmaps; designing, implementing, reviewing, and debugging production embedded software in C/C++ on RTOS-based systems with attention to memory, concurrency, performance, reliability, and maintainability; leading integration across electronics, device UX, wireless connectivity, internal communication layers, mobile applications, MQTT services, REST API, and cloud backends; leading OTA architecture, staged rollouts, rollback planning, validation criteria, and communication of release risks; diagnosing complex field and production issues using logs, telemetry, analytics, lab reproduction, and hardware measurements, and coordinating cross-functional response; identifying and mitigating product-safety, reliability, cybersecurity, and certification risks, and maintaining secure-update, vulnerability-management, and software-lifecycle compliance practices; supporting factory validation, supplier integration, production debugging, legacy products, field service, and long-term maintenance of shipped devices; leading design and code reviews and partnering with various teams (hardware, backend, mobile, product, QA, operations, customer experience, external suppliers); and mentoring engineers, improving development and release processes, maintaining documentation, and utilizing AI-assisted engineering tools.

Requirements

8+ years of embedded or firmware engineering experience, including ownership of system architecture or technical leadership for production products.
Expert-level C/C++ development and strong command of RTOS concepts, embedded architecture, memory management, concurrency, interfaces, and performance optimization.
Experience delivering connected devices from prototype through manufacturing, release, field operation, incident response, and long-term maintenance.
Demonstrated ownership of firmware releases, OTA delivery, validation strategy, and cross-system debugging using real hardware, logs, telemetry, and test data.
Ability to reason about electrical, thermal, control, reliability, safety, and cybersecurity risks and turn that analysis into practical engineering decisions.
Autonomy of decision making and execution with supporting evidence.
Strong written and verbal communication with the ability to align hardware, firmware, backend, mobile, product, QA, operations, and supplier teams.
Bachelor’s degree in Computer Science, Electrical Engineering, Computer Engineering, or a related field, or equivalent practical experience.

Nice To Haves

Experience with MQTT, REST, Wi-Fi, BLE, or comparable IoT protocols and device-to-cloud architectures.
Experience designing robust OTA systems, including partitioning, rollback, staged deployment, fleet diagnostics, and release observability.
Experience with LVGL or comparable embedded UX frameworks and with communication layers between UX, control, and connectivity subsystems.
Experience integrating embedded products with AWS or comparable cloud services and mobile applications.
Experience with device analytics, observability, field diagnostics, reliability monitoring, and data-informed release decisions.
Experience with PID or other control systems, thermal systems, appliance electronics, power electronics, or sensor integration.
Experience with factory validation, supplier collaboration, certification testing, production debugging, and legacy-device support.
Familiarity with RED, EN 18031, the Cyber Resilience Act, secure software updates, vulnerability management, software bills of materials, or related connected-product compliance practices.
Experience applying AI-assisted tools to coding, review, analysis, documentation, or test workflows while maintaining engineering rigor.

Responsibilities

Own firmware and connected-system architecture across Fellow’s products; define clear interfaces, engineering standards, technical roadmaps, and pragmatic tradeoffs.
Design, implement, review, and debug production embedded software in C/C++ on RTOS-based systems, with close attention to memory, concurrency, performance, reliability, and maintainability.
Lead integration across electronics, device UX, wireless connectivity, internal communication layers, mobile applications, MQTT services, REST API, and cloud backends.
Lead OTA architecture, support staged rollouts, rollback planning, validation criteria, and communication of release risks and outcomes.
Diagnose complex field and production issues using logs, telemetry, analytics, lab reproduction, and hardware measurements; coordinate cross-functional response through resolution.
Identify and mitigate product-safety, reliability, cybersecurity, and certification risks; help maintain secure-update, vulnerability-management, and software-lifecycle compliance practices.
Support factory validation, supplier integration, production debugging, legacy products, field service, and long-term maintenance of shipped devices.
Lead design and code reviews and partner with hardware, backend, mobile, product, QA, operations, customer experience, and external suppliers.
Mentor engineers, improve development and release processes, maintain decision and system documentation, and use AI-assisted engineering tools where they improve quality or speed.