IoT platfroms come with their marketplaces, where ready-to-use solutions are offered to the users, whteher developed by the vendor or by partners. The goal of this thesis is to capture the platfroms' users perspective and assess their decisons as they develop IoT solutions. For example, when and why do they use ready-to-use building blocks? When do they need to develop modules on their own? What drives their choice of the platform or modules? What are the challenges they encounter? etc.