Robby on Rails

...back in Portland after being in London and New York City for the past two weeks. It’s nice to be home. :-)

I came across this interview with Matz earlier today. It was published almost three years ago (pre-Rails)... I’m quite intrigued by what he is advocating here…

Bill Venners: You also mentioned in your ten top tips: “Be nice to others. Consider interface first: man-to-man, man-to-machine, and machine-to-machine. And again remember the human factor is important.” What do you mean by, “consider interface first?”

Yukihiro Matsumoto: Interface is everything that we see as a user. If my computer is doing very complex things inside, but that complexity doesn’t show up on the surface, I don’t care. I don’t care if the computer works hard on the inside or not. I just want the right result presented in a good manner. So that means the interface is everything, for a plain computer user at least, when they are using a computer. That’s why we need to focus on interface.

Some software people—like weather forecasters, the number crunchers—feel that the inside matters most, but they are a very limited field of computer science. Most programmers need to focus on the surface, the interface, because that’s the most important thing.

Bill Venners: You also mentioned machine-to-machine interfaces, so are you just talking about interfaces for users or also for machines?

Yukihiro Matsumoto: It’s not just user interfaces. When machines are talking to each other via a protocol, they don’t care how the other is implemented on the inside. The important thing is the proper output getting passed correctly via the proper protocol. That’s what matters.

If you have a good interface on your system, and a budget of money and time, you can work on your system. If your system has bugs or is too slow, you can improve it. But if your system has a bad interface, you basically have nothing. It won’t matter if it is a work of the highest craftsmanship on the inside. If your system has a bad interface, no one will use it. So the interface or surface of the system, whether to users or other machines, is very important.

One of things that we’re really advocating with Dialogue-Driven Development is artifact generation. Wireframes and lightweight prototypes are great for generating constructive dialogue between clients, users, and our team. We should make sure that we understand why and how users will use an interface before we worry about the code that will drive it. Too often we fall into a pattern of thinking where we’re convinced that we can build an agnostic application that has various interfaces to a central repository of business logic and data. While we strive for this during development, it really should be focused on after some initial interaction design has been planned. Of course, this is my opinion.

So, I must ask you. When you’re working with on a new project, do you focus on interface or code implementation first?