It’s an interesting challenge. Modern recommendation systems grew powerful because of enormous amounts of instant feedback. You can capture clicks and view time on the web. You don’t get that in books.
I see three possible solutions:
1. Google approach: scrape the web for book recommendations and somehow create an ML recommendation system that’s better than Goodread’s
2. Pandora Radio approach: (semi-)manually create classifiers for books (genre, tone, character traits, etc.) and build a recommendation system with that.
3. Practical approach: find book reviewers whose opinions you trust and follow their recommendations.
