Building Evolutionary Architectures, 2nd Edition

Chapter 1. Evolving Software Architecture

Building systems that age gracefully and effectively is one of the enduring challenges of software development generally and software architecture specifically. This book covers two fundamental aspects of how to build evolvable software: utilizing effective engineering practices derived from the agile software movement and structuring architecture to facilitate change and governance.

Readers will grow to understand the state of the art in how to manage change in architecture in a deterministic way, unifying previous attempts at providing protection for architecture characteristics and actionable techniques to improve the ability to change architecture without breaking it.

The Challenges of Evolving Software

bit rot: also known as software rot, code rot, software erosion, software decay, or software entropy, is either a slow deterioration of software quality over time or its diminishing responsiveness that will eventually lead to software becoming faulty.

Teams have long struggled with building high-quality software that remains high quality over time, including adages that reflect this difficulty, such as the varied definitions of bit rot shown above. At least two factors drive this struggle: the problems of policing all the various moving parts in complex software, and the dynamic nature of the software development ecosystem.

Modern software consists of thousands or millions of individual parts, each of which may be changed along some ...