Jason Barnard does these awesome interviews on his YouTube channel and one he just recently released was with Nathan Chalmers, the Program Manager, Bing Search Relevance Team at Microsoft. Here is the video interview and the tidbits summarized by Glenn Gabe on Twitter.

Tidbits from the interview:

Darwin: The name of the algorithm that does rich element replacements
Six unique teams work on different areas of the search results page
Bing uses various metrics to track searcher satisfaction of the search results
The main algorithm for ranking helps determine if the search results gets richer elements
Answer placement is mostly based on in intent type and market
The rankings are machine learning based, no one is coding ranking but rather they are coding machine learning models
and much more, with GIFs from Glenn

Forum discussion at Twitter.