[philsnow]

I have made software architecture diagrams, but more "descriptive" than "prescriptive" ones, by generating graphviz from source code analysis tooling. (The objective here was getting oriented in a large codebase where there wasn't really a rigorous diagram of anything written down anywhere, and trying to find sort of a min-cut where putting a line through the graph of imports would cross the fewest edges)

In my experience graphviz handles up to thousands of nodes and tens of thousands of edges without really breaking a sweat.

edit: I've done the same thing with extracting AWS diagrams from aws describe* calls, with good results.