[yarinr]

> I suppose what I am looking for are videos where people walk you through some really advanced open-source applications and explain the application structure and design decisions they have made. That could be relevant for all sorts of tech stacks and combinations.

If that's what you're looking for, consider checking out 'The Architecture of Open Source Applications' here http://aosabook.org/en/index.html

It's not in video form, and the focus, as the name suggests, is on the architecture more than on the tech stack, but you might find it useful.