The software development ecosystem is constantly changing, providing a constant stream of new tools, frameworks, techniques, and paradigms. Over the past few years, incremental developments in core engineering practices for software development have created the foundations for rethinking how architecture changes over time, along with ways to protect important architectural characteristics as it evolves. This practical guide ties those parts together with a new way to think about architecture and time.
We changed the structure from the first edition to more clearly delineate the two main topics: the engineering practices for evolving software systems and the structural approaches that make it easier. In Part I, we define the various mechanisms and engineering practices that teams can use to implement the goals of evolutionary architecture, including techniques, tools, categories, and other information readers need to understand this topic.
Software architecture also involves structural design, and some design decisions make evolution (and governance) easier. We cover this in Part II, which also includes coverage of architecture styles as well as design principles around coupling, reuse, and other pertinent structural considerations.
Virtually nothing in software architecture exists in isolation; many principles and practices in evolutionary architecture involve the holistic entanglement of many parts of the software development process, which we cover in Part III.