Large service organisations like banks have a hard time keeping grips on their software landscape. This is not only visible while performing maintenance on existing applications but also when developing new applications. One of the problems they face is that there are often no clear and uniform descriptions of their products like savings- and current account, loans and mortgages. This makes it hard to reason about changes to existing products and hampers the introduction of new ones. To counter this problem we introduce Rebel, a DSL for product specifications. Rebel lets users specify their product in a high-level, unambiguous manner. These specification can then be simulated which enables users to explore their products before they are build.