The blog post revisits the topic of Interactive Voice Response (IVR) systems and demonstrates building an IVR using Bandwidth's BXML, an alternative to the Voice API that utilizes custom XML for defining phone call operations. Unlike the Voice API, which requires POST requests to update calls, BXML updates are made by Bandwidth retrieving instructions via GET requests from a server, without needing to keep track of call information like the "callId." The post provides a detailed example of setting up an IVR for a customer satisfaction survey within a plumbing service, illustrating how BXML can handle various steps in the survey process by setting up server endpoints that manage call flows and gather user inputs. While BXML can perform the same operations as the Voice API, except for initiating calls, it simplifies the process by letting Bandwidth handle the call updates based on server-provided BXML.