Apple maintains servicetalk[1] (java networking framework built on top of netty), so I'm guessing this is one potential JVM framework that was being used. [1]

Apple maintains servicetalk[1] (java networking framework built on top of netty), so I'm guessing this is one potential JVM framework that was being used. [1] https://github.com/apple/servicetalk https://github.com/apple/servicetalk