Not exactly what you're looking for but I found this to be rather comprehensive:
https://permadi.com/1996/05/ray-casting ... -contents/ Guaranteed, it's very old, but I doubt raycasting is used as a way to render 3D in the industry today.
The tutorial I linked covers from the basics to things the simulating variable height walls, as well as the simulation of looking up/down in a pure raycasting engine. Like Brendan said, this is relatively easier, once you are thorough with the basic idea.
The wayback machine has a few pages backed up, but unfortunately the source code download link seems to not work:
https://web.archive.org/web/20040904052 ... index.htmlBesides, id Software open-sourced Doom, why not look there?
Heck, I still don't believe the Doom engine was a raycaster after all these years. It's probably what you're looking for if you wish to push raycasting to the limit.