Failing to track if the development adheres to the chosen architecture or failing to intentionally plan how the architecture should look will often result in a so-called accidental architecture, and it can happen regardless of applying best practices in other areas, such as testing or having any specific development culture.
There are several anti-patterns that suggest your architecture is accidental. Code resembling a big ball of mud is the most obvious one. Having god objects is another important sign of this. Generally speaking, if your software is getting tightly coupled, perhaps with circular dependencies, but wasn't like that in the first place, it's an important signal to put more conscious effort into how the architecture looks.
Let's now describe what an architect must understand to deliver a viable solution.
