It's all coded in typescript and javascript. I've been toying around with a more in-depth model in web assembly, but as I alluded to elsewhere in this thread, the coding is slow going.
Hey Nicholas, love the tool - great job! I'm working on a new modelling tool (https://causal.app) and built a COVID-19 model myself: https://my.causal.app/models/1432.
This lets you easily run Monte-Carlo simulations. Might be useful for you. But maybe your model is too advanced for Causal.