Interesting project although cant say I am happy to see SQL being used in Streaming Systems like this. In my last two jobs I had to write frameworks and tools to enable "Data Scientists" and "analysts" to write production jobs and problem I have run into with exposing SQL to this class of user is that every job end up being its own special snowflake with deeply nested SQL with custom UDFs mixed in for good measure. Due to "unique" nature of each its significantly increases the support and maintainability cost. I have to come the conclusion that a typesafe api with map/filter/flatmap is much better API to expose that Stringly typed SQL. I am curious to know whether Uber is running into similar support issues?