Welcome Dan Williams, new LibreOffice Developer focusing on UI/UX - The Document Foundation Blog
(blog.documentfoundation.org)
UX is also about code : think about behavior, you may want to prevent any action before one is finished. This is UX and need to be coded.
An other example : I hate how kde's file explorer "dolphin" freezes completely while loading a remote storage. There is no change to be made as UI but a big one to do for the UX.