Bavarian government runs a document template application (RTF or ODF with Groovy, Python, Ruby or Tcl as scripting language) serving different government offices. Having complex and hierarchical data structures to organize the templates, MongoDB was selected to replace the Oracle-based persistence layer. This presentation is about the improvements they have achieved with the migration to MongoDB, problems they had to solve underway and unit testing of the persistence layer in order to keep their quality level. Presentation slides by Christian Brensing, Senior Developer at Rechenzentrum SĂźd, shown at Munich MongoDB User Group Meetup on 18th September 2012