One way to understand the issues that a problematic architecture can cause for CD is to consider a counter-example for a while.
Let's suppose we have a large web application with many different functions. We also have a static website inside the application. The entire web application is deployed as a single Java EE application archive. So, when we need to fix a spelling mistake in the static website, we need to rebuild the entire web application archive and deploy it again.
While this may be seen as a silly example, and the enlightened reader would never do such a thing, I have seen this anti-pattern live in the real world. As DevOps engineers, this could be an actual situation that we may be asked to solve.
Let's break down the consequences of this tangling of concerns. What happens when we want to correct a spelling mistake? Let's take...