You're right. I am actually building billy with my experience and my practices. I have done things with this kind of structure and patterns for tons of projects. Although, I am doing this for years, I am still improving it gradually. 

The reason we have so many discussions here is that we have very different development experience and practices, surely it would take some time to get used to. And yes it would be nice if I can see how you do in the backend systems. I am sure I can learn something from that and apply on billy.

But for now, I can do it with the best productivity in my favor manners (in this week, maybe). So, I will keep working, and in the mean time, I will try get familiar with your style, then gradually refactory and transform into Balanced style. With good testing coverage, we can always switch between different implementation approaches easily. Does it make sense?