Last year I helped organise a coding competition at my university in Hanoi. It was a one-day 'hackathon' held in the engineering building in October, and about sixty students in teams of three had eight hours to build a small app that solved a problem on campus.
I was one of four students on the organising team, and I was responsible for the judges and the scoring system. That meant inviting three lecturers and two people from local tech companies, agreeing on the criteria with them, and designing a scoring sheet that was fair to both first-year and final-year students. On the day itself I also ended up handling the food deliveries, because the person in charge of catering was ill.
The most challenging part, without a doubt, was dealing with a complaint at the end. One team claimed that the winners had used code they'd written before the event, which was against the rules. Suddenly I was in the middle of a heated argument between two groups of friends, with the judges looking at me for a decision. We checked the winning team's files together and found that they'd only reused a small, standard piece of code, which was allowed. But explaining that calmly to a disappointed team was hard. It taught me that rules need to be crystal clear before an event starts, not after. Next time I'd write a one-page rules sheet and get every team to sign it. Even so, the competition was a success, and two of the apps are now actually used by the student union.