An MCU developer designs, programs, and debugs systems using microcontrollers. They write embedded software in languages like C or C++, interpreting schematics and datasheets to understand hardware functionalities. They develop firmware for real-time applications, implement communication protocols, and optimize system performance. They also test and troubleshoot their designs, ensuring reliable and efficient operation. Additionally, they may collaborate with other engineers to integrate the microcontroller with other components, and document their development process for reference and future enhancements. Lastly, they stay updated with latest advancements in microcontroller technologies to improve their design and development skills.