SOA Design Patterns (Repost)

The entire history of software engineering can be characterized as one of rising levels of abstraction. We see this in our languages, our tools, our platforms, and our methods. Indeed, abstraction is the primary way that we as humans attend to complexity—and software-intensive systems are among the most complex artifacts ever created.

I would also observe that one of the most important advances in software engineering over the past two decades has been the practice of patterns. Patterns are yet another example of this rise in abstraction: A pattern specifies a common solution to a common problem in the form of a society of components that collaborate with one another. Influenced by the writings of Christopher Alexander, Kent Beck and Ward Cunningham began to codify various design patterns from their experience with Smalltalk. Growing slowly but steadily, these concepts began to gain traction among other developers. The publication of the seminal book Design Patterns by Erich Gamma, John Vlissides, Ralph Johnson, and Richard Helm marked the introduction of these ideas to the mainstream. The subsequent activities of the Hillside Group provided a forum for this growing community, yielding a very vibrant literature and practice. Now the practice of patterns is very much mainstream: Every well-structured software-intensive system tends to be full of patterns (whether their architects name them intentionally or not).