I'll be sure to do so if/when I build this, in the mean time here are the Show HNs for the recommendation projects I've done so far:

- Music (defunct): https://news.ycombinator.com/item?id=20584508

- Cross-domain (defunct): https://news.ycombinator.com/item?id=23541840

- Essays (still running with ~100 DAU but not actively developed): https://news.ycombinator.com/item?id=24921127

- Newsletters: https://news.ycombinator.com/item?id=27664020