[Exist-open] insight on backend interface

[Robert <st...@st...>]

Hello, 

I'm new to exist but the concept of different storage backends is very
interesting for me. I'd like to investigate how to develop another
backend. I'd be very thankful for any hints where I can find the
relevant interfaces in the source tree and maybe a brief high level
overview how the interaction between "frontend" and "backend" works.
Sorry if such a document already exists, I just couldn't find it on the
website.

Best Regards, 
Robert