SIM Cards running Java run an extremely cut down version of Java that removes basically all features that go beyond what C can do with some sprinkles on top. Th

SIM Cards running Java run an extremely cut down version of Java that removes basically all features that go beyond what C can do with some sprinkles on top. The biggest issue with large Java applications is real and it usually relates to either GC churn or inefficiencies. Source: Running several large java applications as professional sysadmin. Granted, often enough Java is fine, it doesn't use too much overhead, especially once the JVM is warmed up. But the bloat is real and it's partially related to the language itself but plenty of it is also systemic.