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/