Have you seen: https://hnprofile.com/
It's a bit different, but if you can identify what a user is interested in - you could do a good recommendation
It started as an experiment and the initial results convinced me to make an app out of it rather than letting it be an experiment. I believe it's not possible to make a good recommendation system in general, with the limited data available about the community users. Using the HN API, I could only find user's submissions and comments (upvotes are private, thus limiting the amount of useful data). I ended up using only the submissions to determine user's topics of interest.
It's definitely possible, however it would be limited to a subset of users (probably need 10 or 20 comments). When you limit it to submissions the number of words in a title is limited, and often not associated with the actual content itself.