Todd Biske: Outside the Box

The EA Summit has begun and Nick Gall is giving the opening keynote. He’s discussing a “middle-out” architecture style that “enables decentralized change through … minimal constraints.” He’s working hard to not digress into a REST discussion. 🙂 The visual metaphor is an hourglass, where there’s a small set of constraints in the middle that enables things to work, and things that grow outward in both directions. In the upward direction, it’s about the business. Many businesses can all be made to fit within these small constraints. Going down it is about the technology. Once again, there’s a multitude of technologies that can be made to fit those constraints. Many web servers all support the core web protocols.

Beyond the natural ties back to a REST approach, there’s a lot of truth to this metaphor. Both the business and the technology can be viewed as a hierarchical set of constraints. There are a small set of high level constraints that control everything that goes on underneath them. Architecture begins with these, and they are broadly applicable. Put too many of these things in the middle and, as Nick puts it, your waistline grows. If your waistline grows, things get more bloated, and you need more and management, process, etc. to ensure the adoption of these constraints and all of the exceptions associated with them. Doing income taxes comes to mind, for me. How many of the questions on my tax form are applicable to me? Having to go through the process of them makes things more complicated. Many things on the tax forms are so complicated that it’s difficult for an individual to know whether they even apply or not. At the opposite extreme, the narrowest of waistlines would be a standard flat tax. No exceptions, no complexity, just take 17% (or some other appropriate number) and give it to the government. Is there a need to distribute that tax to the local, regional, and federal agencies? Yes, but does that complexity need to be exposed to everyone in the middle? No, it doesn’t. Move it up/down in the hourglass to the areas that care about it, but don’t expose it generally to everyone.

If nothing else, Nick has certainly managed to get me noodling on this whole “narrow waistline” and hourglass approach. It’s a very interesting concept. The immediate concern that I have is that there’s a lot of changes that go on within the sands of the hourglass, and there’s a tendency for things to push toward the middle. To make this work, I think we’ll need appropriate guidance on how to maintain our perfect hourglass shape over time. I suggest using analogies of eating healthy and exercising frequently.