In this episode I get the session message roundtrip working with the simplest possible implementation - all in one method, without any layering. Of course this cannot work in production, but it lets us get started with something that works. After that it's time to do progressive deepening - introduce more layers into the software and push the functionality to the layer where it belongs to - and also do progressive widening - flesh out those layers with more functionality and production-ready quality (see Craftsmanship and Ethics at 18-21 min).
