The Vonage Experience Composer API provides an API-driven cloud service that captures and publishes the entire experience of a web application using the Vonage Video API, allowing developers to record, broadcast, and publish streams with custom elements such as brand overlays, Google calendars, and data tables. This enables richer video call experiences by providing users with multiple streams, including the host's video feed, guest video stream, calendar, overlay, and data table. The Experience Composer API can be integrated with Node.js, Bootstrap, and CSS grid to speed up development time. The application demonstrates how to use the Experience Composer API to create a sample application that allows hosts and guests to interact with each other through multiple streams, including archiving and broadcasting capabilities via HLS or RTMP.