Generative Doom is a plugin for Doom builder that let you create a whole map with a coherent level design given an amount of specific rooms that you can design yourself.
Source GitHub:
https://github.com/Wolfangar/TheBindingOfDoom
Build on Github:
https://github.com/Wolfangar/TheBindingOfDoom/blob/master/Build.zip
Individual Programmer
(Doom Builder Plugin C#)