Part 23 of the series: "Extending bpmn-io Form-JS Beyond Its Limits"

This is the last article in the series. It's also the one to read first.

If you've arrived here without reading the others, this article will show you the complete architecture so you can identify which pieces you need and navigate directly to the relevant articles. If you've read all twenty-two articles before this one, this article assembles them into a coherent whole — showing how every piece connects to every other piece and where the system's decisions were made deliberately versus where they were made under pressure and later regretted.

What Was Built

Over twenty-two articles, the system grew to this:

5 evaluators — classes that run on every changed event and maintain runtime state:

BindingEvaluator — computes derived field values from FEEL expressions

HideEvaluator — toggles field visibility based on FEEL conditions

DisabledEvaluator — applies disabled state from expressions or static flags

RequiredEvaluator — enforces…