This is a remarkable article describing how Faber & Faber (the publishers) are using a series of graphical parts and some custom software to automatically generate book covers for their new series of out of print works.
It works by using a standard layout for things like the title and the barcode, but then using parameterized graphics it generates a unique cover graphic for each book.
The covers fit within the style that has been chosen of course, but each is unique.
It’s really clever.