In 2011, France had a big problem with leaking breast implants.
In order to avoid the same issue in Belgium, we have built several applications for tracking these implants. To subsidize these applications, the Belgian government decided to tax companies who work in the world of medical implanted devices.
Contributions is the application which calculates and invoices taxes. Even more: we make it possible for the business to adapt the business rules and -flow themselves!
Technically, it's a very interesting application, built with a domain driven design, driven under the hood by the Activiti workflow engine.