When a player starts, it incepts a random (whole) number and sends it to the second player as an approach of starting the game. The receiving player can now always choose between adding one of {-1, 0, 1} to get to a number that is divisible by 3. Divide it by three. The resulting whole number is then sent back to the original sender.

You can start the game on your terminal, if you have this requirements:

• java >= 8
• mongodb database
• maven

to start the game on the terminal point to the root of the repo and run this command:

$ mvn spring-boot:run

Or if you have docker with docker-compose, on the root of the repo run this command

$ docker-compose up -d

You can access the game from your browser on http://localhost:8080,

Use different browser sessions for different players.

Multiple games can be played simultaneously.

The game is build using spring-boot, the game persists the state on mongodb database, To join, rejoin or create a game POST request is sent to the API, and for event communication is done with WebSocket and STOMP protocol. The front is build using vanillajs, with STOMP client library, and a simple watcher library.

• Write tests
• Use a message broker system (like rabbitmq or kafka) for queueing STOMP message, in order to easily scale the app.
• Enhance the front, by using a frontend framework or library (like vuejs or react).
• Enhance the user system to keep track of the score
• Secure the communication channels (REST and WebSocket)