A Matter ecosystem is an IoT ecosystem built on top of the Matter fabric concept. As Matter is a local network protocol, other aspects like device management, user management, access control, etc. are left to solution developers. Some popular ecosystems that support Matter are Apple Home, Google Home, and Alexa. ESP RainMaker, which is an end-to-end solution for IoT devices also offers a similar private Matter ecosystem. This talk will explain the various concepts and features of such an ecosystem, with a special focus on a special device type called Matter Controller.