Just explained my project to a new team member and realized UML does not have standard way of expressing data flow diagrams. Indeed, it is an object-oriented toolset, and data flow is so-o-o 1970s.

Yet, even in our perfectly object oriented systems we do have a data flow. Our objects may be viewed as a bunch of filters that crunch data (trade data) translating it from format to format. If you make it a communication, or a sequence diagram, it would look pretty dull:

x ^{___ProcessTrade___}→ y ^{___ProcessTrade___}→ z

That’s the parameter type of ProcessTrade that changes, and this is what makes it interesting. A totally not object-oriented data flow diagram like this:

FixTrade ^___x____→ XML ^___x____→ Database

would be much more to the point. More and more often I recall Steve Yegge’s “Execution in the Kingdom of Nouns“…