All of this is implemented in the demo and elaborated on below in code form, but for more information and very good diagrams on the topic, Gabriel Gambetta did an excellent three part series on the concepts presented - including client prediction, interpolation and the reasons why these work best for real time games. Most important for our example is that we store the input sequence of each input the player gives us. We use this to track where the server is in our list of inputs, and we re-process input that the server has not yet received.