This is a great re-imagining of web application design through the lens of the Lambda Architecture proposed by Nathan Marz. Decomposing problems into pure functions and immutable data structures always seems to tease out these nice ideas. I think this trend of re-imagining long held ideas through these concepts can be traced back to Rich Hickey's work on Clojure (and surely further, but Clojure really set the spark off to me), it's going to be amazing to see all the intellectual dividends that work pays beyond the concrete language itself.

The key though is these abstractions need to be water-tight and as easy to use as their contemporary, side-effecting counterparts. It's just plain easy to rig up a Rails model/controller binary system right now and get things drawing on the screen. It stands clear on the "Easy not Simple" side of things while these new concepts are still very much in the "Simple but not that Easy" side. For these types of architectures to take hold they have to become natural, conventional, and require little extra mental baggage to use them. Fortunately its much easier to make difficult-to-use, simple things easy than complicated, easy things simple. These simple ideas will eventually rise to be easy as well, but as we are in the early wild-west stages of these ideas being turned into systems we are going to see a lot of rapid evolution on the way there.