Projection and updates of nested data structure encoded as Map<String, Object> made elegant via Optics - not a big deal unless one needs to do that in Java. But FunctionalJava’s optics APIs saved my day again. The fact that FunctionalJava is so underused in the enterprise, which still lives in Java-land, is mind-boggling to me. I don’t work in Java anymore but demoing the power of lawful optics via FunctionalJava library was interesting.