Software architecture in a nutshell
However rich the literature is on the topic, it's not so easy to find a common definition of software architecture. We as architects like to decouple things, so let's decouple the words software and architecture. Starting with software, we can give this broad definition: computer programs. Our second word, architecture, can be defined as the art of designing buildings, houses, and the like. If we extrapolate a bit, we could define software architecture as the art of designing computer programs. This definition sounds very broad.
Rest assured, we can evacuate hardware from the equation because it represents the machines themselves. Phew—this should make our task easier, although we are left with everything that runs on a piece of hardware, which remains extremely vast.
Searching for software architecture on Google reveals about 262,000 results, which is very impressive. So many results probably mean a lot of different definitions and a lack of a common understanding of what software architecture is all about. The same query on Google Images does not bring up a single diagram that could help up figure out what software architecture is.
Given the diversity of definitions, I will provide my own, although I don't claim to have the absolute truth. I will start by tying software architecture to the Architecture Tradeoff Analysis Method (ATAM), which we will see in Chapter 3, Understanding ATAM and the Software Quality Attributes. In a nutshell, ATAM consists of evaluating different quality attributes—such as performance, availability, reliability, and so on—of a piece of software. Some of these attributes are code-related, whereas some are infrastructure- or security-related.
Although there is no single definition of software architecture, one thing is absolutely certain: a software architect should be acquainted with ATAM. Another thing that appears as an emerging consensus is that the role of a software architect is tightly coupled with the actual development of an application, and I share this viewpoint. This is how Wikipedia (https://en.wikipedia.org/wiki/Software_architect) defines software architecture, but for me, software architecture goes far beyond mere coding, and that is what you will find out while reading this book. Let's now look at what a software architect's job description might look like.