The blog website isn't written in Elm. We're using Elm for the product application, not for the blog or for https://www.humio.com/.
I'll transfer the remarks though :)
We have, and that's where we reach out to JS/TS through ports or webcomponents. We try to use Elm as much as possible since that's the simplest and the most reliable, but using JS/TS this way is fine in small quantities.