Instead of everything being a white rectangle, make the shapes meaningful representations of what's written inside them. Perhaps include logos or little icons.
Varying colors in a meaningful way can also be helpful.
I am a huge fan of declarative everything, starting with infrastructure. Extending it to database schema and business logic would be absolutely amazing.
I haven't used Java in years, so it's hard to comment on specifics. Do I understand the goal correctly?
What do you generally think about the project (vangav backend), do you find it useful for you or any of your friends?