While Service Oriented Architectures (SOAs) are for many parts deployed online, and today often in a cloud, the testing of the systems still happens mostly locally. In this paper, we want to present the MIDAS Testing as a Service (TaaS), a cloud platform for the testing of SOAs. We focus on the testing of whole SOA orchestrations, a complex task due to the number of potential service interactions and the increasing complexity with each service that joins an orchestration. Since traditional testing does not scale well with such a complex setup, we employ a Model-based Testing (MBT) approach based on the Unified Modeling Language (UML) and the UML Testing Profile (UTP) within MIDAS. Through this, we provide methods for functional testing, sec...