So German Rail is holding an Open Data Hackathon in Berlin.
The date is 12/13. May 2017, the location is DB mindbox, S-/U-Bahnhof Jannowitzbrücke, Holzmarktstraße 6-9, 10179 Berlin.
The event starts on Friday at 4pm, and continues all night and until Saturday, 8pm. You basically have 24h to do something awesome.
Check out their Github at https://github.com/dbopendata.