this java project implements a race ski/snowboard in different arenas using a design pattern like Factory method, Adapter, Bridge, Observer 
State, Proxy, clone, Decorator.
the race is mange by Thread Pools that mange all racer in case of accident/malfunction.  the race is limited up to 20 racers.
for graphic implementation, I use java GUI  Swing and observer pattern to communicate between racers and the location on the screen.
using java 8, IntelliJ IDEA Community Edition 2018.3.4