> ...until strong typing is mandatory in the language, I can't fathom using JS in any sizable project.

There are quite a large number of counter-examples to show type safety isn't especially important to the success of large projects.

I think the guarantees it provides are far too limited and weak to support large software systems. It relies on static code analysis, which doesn't mean much unless your app is a single build and runs as a single instance. That's more of a '90's style Microsoft Word type of app than what a typical large software project is today. Meanwhile the guarantees it does provide are only helpful to the extent developers can map their domain problems to the capabilities of the type system. Sometimes there is a nice natural fit, but usually the typesystem is both too weak (doesn't provide a convenient and natural way to impose the constraits of your problem domain) and too strong (imposes constraints your don't need or want, encumbering your development process).

Not to mention that when it comes to Javascript, you can opt-in to about as much static code analysis, including type-safety, as you want.