When selecting a microcontroller for an embedded system, engineers must consider several key factors. Processing speed and memory capacity are crucial to ensure smooth performance of the application. Power consumption plays a major role, especially in battery-operated devices. Input/output peripherals, communication interfaces, and compatibility with sensors also influence the choice. Additionally, cost, scalability, and ease of programming are important for long-term efficiency. Reliability, availability of development tools, and community support further guide decision-making. Gaining expertise in these aspects can be achieved through an embedded system course.