[runaway]

You can write JS functionally but to get the benefits from the video like modeling your data as sum & product types as well as static type checking, you need to use a language with its own compiler.

For languages that compile to JS, Elm looks a bit more like the F# in the video (https://elm-lang.org/) and Typescript (https://www.typescriptlang.org/) is a much more like standard JS.

[maxdeviant]

You can also use Fable (https://fable.io/) to compile F# to JS.