[agibsonccc]

Disclaimer: I am an oreilly author and have spoken at both hadoop summit at strata multiple times.

Generally: Your luck with the above mentioned conferences are going to be mixed. There's a ton more biased content towards machine learning now.

Spark summit and flink forward might be better for you. Those are more systems focused: http://sf.flink-forward.org/ https://spark-summit.org/

There's also kafka summit: https://kafka-summit.org/