I don't have a good image for this subject.
I learned something new about linux permissions. As long as the immediate parent directory is user writable you can write to it, even if that parent directory lives in a non user-writable directory.
For example:
/usr/ # drwxr-xr-x root:root
/share/ # drwxr-xr-x root:root
/nas_folder # drwxr-xr-x na:na <-free to read and and write by na
All these years I've assumed you needed writeable parents all the way down. This changes how I would organize my web service directories.
Maybe when my sbc explodes and I have to rebuild everything I'll organize things better.