Daily.co has introduced track subscriptions, which allow participants to dynamically control who can see each other's tracks (microphone, camera, screenshare) in a call. This feature enables more granular control over media tracks and saves CPU cost by only decoding required tracks. A suggested use case is for the last person to join to introduce themselves, where all participants will see and hear that participant, but no one else. To get started, developers need a meeting token with `is_owner` set to `true`, and can use a pre-built UI demo to test track subscriptions. The demo uses the new `subscribeToTracksAutomatically` instance method and custom callback functions to subscribe and unsubscribe participants' tracks as they join or leave the call. With this feature, developers can create more engaging large meetings with dynamic control over media tracks.