IoT and embedded covers programming for microcontrollers, single-board computers (Raspberry Pi, ESP32, STM32), and the wider Internet-of-Things stack: sensors, gateways, MQTT brokers, cloud-side device management, and the security model around long-lived devices in the field.
The toolchain depends on the target. Arduino and MicroPython are entry-level; ESP-IDF, PlatformIO, and Zephyr RTOS handle production-grade development. On the cloud side, AWS IoT Core, Azure IoT Hub, and Google Cloud IoT Core (deprecated) compete with self-hosted alternatives like Mosquitto and EMQX. The hard part is rarely the firmware — it's OTA updates, certificate rotation, and the operational lifecycle of devices that must run for years without intervention.