Here is a graph representation of their SysDB architecture, I am not an expert, but it was described to me as in-state database with a pub/sub model. Each of the little circle is an agent that exchange their state information to the central SysDB and receive other information about the box back. In reality, it means we can separate out the components and get a more stable box when something bad happens. Juniper used to be the standard at this, but now I think it is Arista.
Here is the company's web site:
Here are two links to the location where you can see some example of the scripts:
EOS Central Dev Blogs
In later sections I will pick out some of the more useful scripts that I find.