How does this help me build maintainable software?

Component-based architecture is very simple. As long as each component has a dedicated namespace, dedicated API and internal packages, and classes within an internal package are not called from the outside, we get a very maintainable code base consisting of many composable and re-composable components. If we add the rule that components may be composed of other components, we can build a whole application out of smaller and smaller parts where each part solves a simpler problem.

Even though there are loopholes to get around the rules of the component architecture, the architecture itself is so simple that it’s very easy to understand and communicate. If it’s easy to understand, it’s easy to maintain. If it’s easy to maintain, the loopholes are less likely to be exploited.

Hexagonal Architecture cares about boundaries at the application level. Component-based architecture cares about boundaries at the...