The Planets project develops a service-oriented environment for the definition and evaluation of preservation strategies for human-centric data. It focuses on the question of logically preserving digital materials, as opposed to the physical preservation of content bit-streams. This includes the development of preservation tools for the automated characterization, migration, and comparison of different types of digital objects as well as the emulation of their original runtime environment in order to ensure long-time access and interpretability. The Planets integrated environment provides a number of end-user applications that allow data curators to execute and scientifically evaluate preservation experiments based on composable preservation services. In this paper, we focus on the programming environment and show how it can be utilized in order to create complex preservation workflows. We argue that preservation systems in particular have strong dependencies on legacy applications and third party services. Therefore, research on unified preservation interfaces, standardized service profiles, and programming models is crucial to the interoperability and reusability of current and future preservation tools and components.