A recommendation system can improve its headline metric while making the marketplace feel narrower. I care about both the immediate result and the distribution it creates.
I have worked on recommendation experiences across homepages and ad-detail pages in classifieds and motors. The work involves model comparison, experiment design, result analysis, and questions that are harder to compress into one metric—particularly diversity and the balance between relevance and discovery.
01Homepage and ad-detail recommendation surfaces
02General classifieds and motors marketplaces
03Offline evaluation and controlled product experiments
04Relevance, discovery, freshness, and diversity trade-offs
One example
Measuring diversity as a distribution
I used KL divergence to compare the distributions produced by recommendation approaches. It gave us a way to discuss diversity as an observable model property rather than a subjective impression of the feed.