The interesting things are in my opinion that Redis is the sole backend, the code is simple, and no Redis operation was "forced" to do something that was not the natural goal. In practice this example shows how the Redis data model is a natural way to model complex needs without a line of SQL and without any need to setup indexes or things like that. I think this is a pretty important point.

Another interesting technical detail is that the whole site uses only an HTML template and everything else is done via javascript using jquery.