The most useful definition (for engineering) is that "code" changes/defines how the program executes. Your YAML shopping list changes your path through the shop

The most useful definition (for engineering) is that "code" changes/defines how the program executes. Your YAML shopping list changes your path through the shop, so it is code. For non-trivial programs the configuration space is so large that it's impractical to test every single configuration during development, so instead the operators are expected to test before putting into production.