"Scala in particular with its immutability generates a lot of garbage if you are not careful, and we were constantly fighting GC pressure (and, indirectly, our

"Scala in particular with its immutability generates a lot of garbage if you are not careful, and we were constantly fighting GC pressure (and, indirectly, our achievable concurrency and efficiency) at a household name Scala app. The number of JVM developers who are aware of this and capable with the memory subsystem -- i.e., off-heap strategies such as that used in Flink (relevantly) and some of the clever speedups in netty -- are dwarfed by the number of JVM developers in the whole, so you really need someone who understands these problems to efficiently scale a JVM language." Jed, once again you are laying claim to experience you do not have. If you ever once had touched Scala at Foursquare it would be a different story. This is just a bunch of tired platitudes.