Organizations operating in a network require strong information technology support to successfully collaborate. In a business service network, the links between partners must enable quick connect and disconnect relationships, in order to harness market opportunities. Scholars claim that information technology platforms are necessary to enhance this quick connect capability and to transform business networks into digital ecosystems. However, the state of the art in inter-organizational collaboration relies on static collaboration patterns between individual partners, and current systems are engineered without interoperability in mind. In this study, we follow a design science approach to promote the concept of platform-based collaboration. More precisely, we propose an architecture for an inter-organizational platform that facilitates the provisioning of collaboration services. Furthermore, we present a prototype in the context of e-commerce as a means of evaluating the proposed design. We conclude that the platform approach is beneficial in achieving increased flexibility in business-to-business collaboration.