Most System Dynamics (SD) software still treats a model like a slide deck. I wrote a short piece arguing that models should live as code—versioned, tested, observable, and fed by real‑time data—just like any service. It sketches the platform building blocks (registries, query engines, runtimes) rather than pitching a monolith.

I’m interested in counter‑arguments: where does the diagram‑first approach still win?