DJHell .'s List: Evolutionary architecture and emergent design at developerWorks

"Software architecture and design generate a lot of conversational heat but not much light. To start a new conversation about alternative ways to think about them, this article launches the Evolutionary architecture and emergent design series. Evolutionary architecture and emergent design are agile techniques for deferring important decisions until the last responsible moment. In this introductory installment, series author Neal Ford defines architecture and design and then identifies overarching concerns that will arise throughout the series."

"Most developers think that the most beneficial part of using test-driven development (TDD) are the tests. But, when done right, TDD improves the overall design of your code. This installment in the Evolutionary architecture and emergent design series walks through an extended example showing how design can emerge from the concerns that float up from testing. Testing is only a side effect of TDD; the important part is how it changes your code for the better."

"Testing is only a side effect of test-driven development (TDD); when done right, TDD improves the overall design of your code. This Evolutionary architecture and emergent design installment completes a walk-through of an extended example showing how design can emerge from the concerns that float up from testing."

"How do you find hidden design in aging code bases? This article discusses two important patterns for code structure: composed method and single level of abstraction. Applying these principles to your code allows you to find reusable assets that remained hidden before, with the further benefit of letting you abstract existing code into harvested frameworks."

Earlier installments in this series discuss how unit testing leads you to a better design. But if you already have lots of code, how do you discover design elements lurking within it? The preceding installment talked about building structural targets for your code. In this article, series author Neal Ford expands on those ideas and covers techniques that use refactoring to allow emergent design."

Some of the common questions relating to cyclomatic complexity are "How does my code compare to others?" and "What is a good number for a particular class?" The iPlasma project answers these questions (see Resources). iPlasma is a platform, created as a university project in Romania, for quality assessment of object-oriented design. It generates a pyramid, showing key metrics for your project along with comparisons to industry-standard ranges for those numbers.

"The ability to see and harvest idiomatic patterns is critical for emergent design. Also vitally important to design is code's expressiveness. In a two-part article, Neal Ford discusses the intersection of expressiveness and patterns, demonstrating these concepts with both idiomatic patterns and formal design patterns. He recasts some of the classic Gang of Four patterns in dynamic languages for the JVM to show how more expressive languages enable you to see design elements obscured by more opaque languages."

"The ability to see and harvest idiomatic patterns is critical for emergent design. Also vitally important to design is code's expressiveness. In Part 2 of this two-part article, Neal Ford continues discussing the intersection of expressiveness and patterns, demonstrating these concepts with both idiomatic patterns and formal design patterns. He recasts more of the classic Gang of Four patterns in dynamic languages for the JVM to show how more-expressive languages enable you to see design elements obscured by more-opaque languages."

"This installment ties together emergent-design concepts from previous Evolutionary architecture and emergent design articles with a case study that shows how to discover, harvest, and leverage unexpected design elements in code. Once you understand how to identify design elements, you can use that knowledge to improve your code's design. Emergent design allows you to discover aspects of your code that you could never anticipate yet have become important parts of your code base."