Phil Windley (former CTO of Utah!) writes about Running Code and Regular Releases:
Several interactions I’ve had recently with groups building Web applications have led me a renewed appreciation for the power of running code in a development project. Both of these organizations were some time into a large development project and still didn’t have running code and regular, consistent release cycle. This wisdom gets great lip service, so it surprises me to see people who should know better not following it.This blows my mind. I have never been in a situation on the web where I didn't have running code. Release cycles vary from project to project, but I can not think of a situation where you don't have running code.
Yesterday, I moved my code off of the Zope instance I tend to use for development and into a separate instance (a separate running Zope server). I first moved my core application, along with its two supporting frameworks - one for the data management the application is built on, one for the simple workflow engine the application uses - into the new location. I fired off my unit tests and they all passed in the new location, even without having all of the supporting Zope Products in place yet that were used by the web interface. It was gratifying to see that all my tests succeed and know that the application could, at this point, move just about anywhere. And that I had a reasonable assurance of its success by having so much running code in place already.
Perhaps I've lived too long in the world of dynamic languages like Python where the compilation step is absent. Or perhaps it's that I first started programming on a machine with an omnipresent BASIC interpreter which allowed me to see immediate results. I've never been able to fathom a world of blind design-and-hope development. I could see how large systems with scarce resources were scarce could be built this way, but those should be few and far between now.