At Positive Grid, we are committed to delivering award-winning hardware products and innovative solutions in the music technology space — the Spark amplifier family and the software that runs with it, sold in over 100 countries. We are looking for a firmware engineer to join our Firmware team and own product firmware delivery on our STM32 and ESP32 platforms. You will take ownership of the ESP32 connectivity stack and the USB firmware-update toolchain — two capabilities that sit underneath every connected product we ship — and drive STM32 firmware development across our product lines, from feasibility studies through to mass production.
【Key Accountabilities】
- Own the connectivity layer — take ownership of the ESP32 connectivity firmware (BLE / WiFi) shared across all connected products
- Own the update path — take ownership of the USB firmware-update toolchain, the desktop-side update route for every product we ship
- Build the product firmware — design and develop firmware on STM32 (Cortex-M4/M7) platforms, integrating MCU functionality, peripheral drivers and DSP algorithms
- Develop and maintain C/C++ components covering audio routing, looper functionality, and mobile-to-firmware communication protocols
- Debug and tune — manage firmware performance trade-offs across speed, memory footprint, development cost and recurring cost
- Carry firmware through NPI — translate PRDs into actionable engineering specs, and take firmware deliverables through the NPI gates, including feasibility studies, risk assessment and contingency planning
- Work with ODM partners on firmware-side deliverables: align tasks, review their firmware design, and keep schedules on track
- Work directly with hardware engineers on hardware/software interface issues, and give firmware-perspective input on circuit design
- Collaborate with the mobile, application and product teams so firmware integrates cleanly into the overall product experience
- Uphold engineering rigour through code reviews and root-cause analysis
【Essential Requirements】
- Bachelor's or Master's degree in Computer Science, Electrical Engineering, or a related field
- Minimum of 5 years of work experience, including at least 3 years in MCU or RTOS development
- Proficient in C and competent in C++
- Strong understanding of common hardware interfaces (I2C, SPI, UART, etc.)
- Hands-on bare-metal MCU development on STM32 (Cortex-M4/M7) or an equivalent platform
- At least one product taken all the way through to mass production
- Able to own a firmware module end-to-end and independently — from spec through to release
- Able to read schematics and work alongside EE on hardware bring-up and interface issues
- Familiarity with Git
- Excellent team communication skills
【Desirable Requirements】
- BLE protocol stack experience (GATT, connection parameters)
- ESP32 / ESP-IDF experience, ideally taken through mass production
- RTOS experience (FreeRTOS)
- USB device development (CDC / DFU)
- Strong ability in memory management and performance optimization
- Experience in IoT product development
- Audio product background, or consumer electronics / music technology experience
- Basic hands-on rework — soldering, jumper wires — for bring-up and debug
- Practical day-to-day use of AI coding agents (Claude Code, Codex or similar) as part of development, code review, debugging, documentation and test automation — with concrete examples of what it changed
- Proactive problem-solving skills
- Passion for music
