I've been working with some different frameworks lately. One of them is Zend Expressive, and I've come to the conclusion that I don't need to choose between different frameworks; depending on the project, Expressive always fits my needs and scales from small projects to bigger applications.
He starts off by looking at the "microframework approach" that Zend Expressive takes, making it easier to get up and running for smaller applications. He points out that this setup is fine when the application is small, but what happens as it grows - it just wouldn't scale well and be manageable. He talks about the setup he uses for larger scale applications, moving the configuration to dynamic config files and making use of more complex dependency injection. He also talks some about modularity in applications, the "middleware paradigm" and how he set up controller-style dispatching (versus just the default closures method).