Bokeh and anywidget

[peekxc]

Is there any advice on how to develop a custom extension w/ Bokeh in ways that are compatible with anywidget?

I'm trying to build custom extension using Bokeh's extension API, but it's slow, difficult, and error-prone to do due to a things like the (large) typescript source and the lack of a progressive dev workflow. I also just don't know Bokeh's TS source well enough to make certain decisions which lie very far outside of whats documented (when is is appropriate to extend LayoutDOMView vs LayoutDOM? What are the interactions between a given model and bokeh figures? How do I handle callback events like selections?)

What's the workflow like for the core Bokeh developers? What tools do you use to e.g. debug Python / JS interactions and verify functionality?