The objective of this paper is to present the software architecture used for the OPERANDO privacy platform, funded by the European Union in a Horizon 2020 project. For integration, OPERANDO is using SwarmESB, an open source Enterprise Service Bus (ESB) based on executable choreographies. In this paper we are presenting the concept of service transformations, presented as a bridge between the world of REST web services and the world of services implemented with executable choreographies. These transformations are improving the heterogeneity aspects when we are analysing SwarmESB as a distributed system. Five types of transformations that have been analysed and implemented as open source software have been integrated. This proposal is shaped around a common language capable of expressing all these five transformation types we have identified working for OPERANDO. Therefore, the Domain Specific Language proposed, renders the essential elements for transformations among functions, web services and executable choreographies. This unification will trigger a quantitative effect on the productivity of the teams creating or integrating web services in a federated service bus environment which is a key architectural component in the future Internet-of-Things and cloud systems.