Hey @KeksHD (by that name I guess you speak german, welcome here, there are many of us)
I just took some time to explain the requirements and more of developing LU in some detail, after reading this post. Have a look at it on my blog over here: https://xiphosia.wordpress.com/working-on-lu/. I hope this clears it up a bit. There is a lot more information on that blog if you are interested.