ESP32 firmware engineering for ESP-IDF projects. This skill encompasses writing, reviewing, and debugging embedded C/C++ code, including FreeRTOS, peripherals (GPIO, I2C, SPI, UART, ADC, PWM), TWAI/CAN, Wi-Fi/BLE, OTA updates, Secure Boot, flash encryption, and LVGL display integration. It also covers build/flash/monitor workflows, logging, crash analysis, optimization, low-power design, service terminals, and board bring-up.