It's a complex minecraft minigame network containing multiple modules.
The project uses:
Redis to cache user's data to save time on data write/read and to send messages between spigot servers, for example when we need to send player to another game;
MongoDB to save user's data once they left network
Spigot (+ 1.8.8 NMS) and Bungeecord APIs
Lombok + some extra libraries such as commons-io and caffeine