Large cities face many challenges, from gridlock and lack of space to rising costs for equipment and energy. The EDAG CityBot is a concept that aims to solve these problems. CityBots can transport people and goods, but also work for the community and the citizens. Their ecosystem includes traffic control and closed-loop engineering to keep them running continuously, and a safer, greener city integrating local manufacturing. After an introduction to the ecosystem the design process of this multi-year project is shown from the first sketches to a functioning prototype, and also a preview of the upcoming real world testing.