After some market consolidation happening mostly between 2011 and 2013, IoT products are now hitting the market across all segments: consumer (wearables, home automation), commercial (HVAC, parking) and industrial (industrial process control, supervision). Often driven by the fear to “fall behind”, small and large companies push their engineering teams to productize solutions quickly. If those companies choose to implement standards-based products, the compliance testing, interoperation testing and labeling of their product may take over a year, which is often unacceptable giving todays rush-to-market. Companies therefore often go for in-house proprietary solutions, which can be developed and tested much faster. The result is that the market is highly fragmented: a large number of non-interoperable solutions are being installed, eventually leading to increased cost, inefficiencies, customer frustration, and a rate of adoption of the IoT much slower than the numbers touted by analysts. The market is now at a state where we need to think about interoperability. What does it take to make different IoT solutions seamlessly integrate with one another? Are there architectures and tools one could develop to speed up interoperability testing? If interoperability isn’t feasible or desired, can we at least build in mechanisms for different product to coexist? The goal of this conference is to bring together practicing engineers and advanced researchers to share the state-of-the-art around interoperability in the IoT, analyse what is needed, and identify the work that lies ahead to increase the number of interoperable IoT products.