How do you/AirBnB handle deeply linked features (2-hop+?) that are also latency sensitive? Maybe I'm missing something, but I don't imagine that with the transformation DSL described in Chronon.

For our org, those are by far the most complicated to handle. Graph DBs are kind of scaling poorly, while storing state in stream processing jobs is way too large/expensive. Those would also be built on top of API sources, which then lead us to the unfortunate "log & wait" approach for our most important features