I find the Hadoop platform to be heavyweight and difficult to manage. Its design came from the original GFS and MapReduce papers, and was perhaps not great to begin with (name nodes failover, etc.).

I would like to see the industry move away from the JVM to less memory-hungry, AOT-compiled languages. Too much of the Hadoop world simply assumes that you'll be using a JVM language, and don't provide non-JVM APIs at all. It's been a while since I looked, but I think Apex and Flink were basically useless if you didn't use a JVM language or Python.

Of all the Apache projects related to Hadoop, I believe Beam is the only one that has Go support (for implementing processing logic), for example.