That is an excellent resource, thank you!
I like the idea of the entire guide being rooted in a single page that specifies all of the architectural blocks (and messaging/calls between them) in summary. With the summary in a named heading, telling the name, description, and source code filespecs & DB tablenames / config filespecs, linked to another page detailing that component programming notes, like data format and other lower level detals. Like for example its link in a chain of code paths in a given use case. Then we can link pages in the main wiki that are consumer user documentation to their developer's guide summary section on the main page, clickable to more detailed info on its own page.
It would also be very valuable for the programmer's guide subpages each to specify which version of LMCE and the component is being documented. Including those version numbers in the page editor's summary field when updating it for a new version will let later readers just find their old version's docs (if it exists) by looking at the page's history tab.
Thanks again for kicking this off! I encourage everyone who can to at least add source code filespecs and DB tablenames / config filespecs to any section they know is relevant.