In November we invited hackers to improve the sustainability on dairy farms at the Bright Cow Hackathon 2017 event. 22,000 visitors at the Official Bright Day event watched 6 teams of hackers, software designers and data scientists compete to come up with smart solutions for the dairy chain. Using real data on Dutch cows, for example on their food intake, milk yield and location (GPS), the teams worked two days on ideas to make dairy farming more sustainable.