As there are plenty of options for architectural styles, you may have gotten a bit confused in this chapter. You'll have to consider the tradeoffs for each one of them in order to choose wisely. One thing is clear: the Big Ball of Mud approach is not an option, as the code will rot pretty fast. Layered Architecture is a better option, but it presents some disadvantages, like tight coupling between layers. Arguably, the most balanced option would be Hexagonal Architecture, as it can be used as a foundational base architecture, and it promotes a high-level degree of decoupling and symmetry between the inside and outside of the application. This is what we recommend for most scenarios.

We've also seen CQRS and Event Sourcing as relatively flexible architectures that will help you in fighting serious complexity. CQRS and Event Sourcing both have their places, but don't let the coolness factor distract you from the value they provide. As they both come with some overhead, you should have...