Today, the IoT landscape consists of a large number of vertical IoT platforms that are rarely interconnected. To enable creation of applications across platforms and domain boundaries interoperability needs to be established between IoT platforms. In this paper we present how this task can be simplified by utilizing a systematic software development process based on behavior- and domain-driven development. This process is illustrated using an example that uses the open source IoT interoperability framework symbIoTe to connect two indoor navigation platforms. We show that developers can actually profit from this approach but existing IoT interoperability frameworks are still cumbersome to use.