Software Architecture Patterns, 2nd Edition

Chapter 1. Introduction

It’s all too common for developers to start coding an application without a formal architecture in place. This practice usually results in ill-defined components, creating what is commonly referred to as a big ball of mud. These architectures are generally tightly coupled, brittle, difficult to change, and lack a clear vision or direction. It’s also very difficult to determine the architectural characteristics of applications lacking a well-defined architectural style. Does the architecture scale? What are the performance characteristics of the application? How easy is it to change the application or add new features? How responsive is the architecture?

Architecture styles help define the basic characteristics and behavior of an application. Some architecture styles naturally lend themselves toward highly scalable systems, whereas other architecture styles naturally lend themselves toward applications that allow developers to respond quickly to change. Knowing the characteristics, strengths, and weaknesses of each architecture style is necessary to choose the one that meets your specific business needs and goals.

A lot has happened in software architecture since 2015 when the first edition of this report was published. Both microservices and event-driven architecture have gained in popularity, and developers and architects have found new techniques, tools, and ways of designing and implementing these architecture styles. Also, the widespread use of domain-driven ...