First, to clarify - what is "code", what is "data"? In this article, when I say "code", I mean something a human has written, that will be read by a machine (another program or hardware). When I say "data", I mean something a machine has written, that may be read by a machine, a human, or both. Therefore, a configuration file where you set logging.level = DEBUG is code, while virtual machine instructions emitted by a compiler are data. Of course, code is data, but I think this over-simplified view (humans write code, machines write data) will serve us best for now...