Link to relevant page (if any): https://prosody.im/doc/developers/architecture
What's wrong and how can it be improved?
This page is out of date, 'connlisteners' were removed in 0.8 or so, and quite a lot of session logic is has moved into mod_c2s and mod_s2s.
Also, all links are broken.
In general, introductory documentation covering the project layout and architecture seems to be missing. Having this would be good for new potential contributors.