A software application is related to the processes it supports. Today, UML diagrams esp. use case diagrams and activity diagrams are often used to model the relevant aspects of the processes within the analysis phase. In the design phase the models are manually mapped to the business layer of the software application. In the context of Service-oriented Architectures (SOA) Programming in the Large takes a different approach: Business processes are described in a programming language, i.e. a process language which can be automatically mapped to an execu-tion language and executed by a process engine. In this article we show how Programming in the Large can be practically applied in a software engineering process. We use the Business Process Model Notation (BPMN) as process pro-gramming language. A BPMN description can be mapped to the Business Process Execution Language (BPEL) which is a widely accepted standard to compose Web services.