Any story you click takes you to their domain somehow but it’s clearly ran off of Medium’s platform and they do have their own page here.
I’m Doing Better As a Writer on Medium Than The Local Newspaper Who Turned Down Hiring Me Five…
Brian Brewington
2793
Reading that, I remembered a strange case.
I once stumbled on a publication like you say, with the custom domain but run outside Medium, with additional features, features not accessible to us mortals. I protested with Medium, and Medium blocked the “redirection” which probably exploited a legacy feature of the Medium old days. Sorry for that publication, but I like fair games.
Anyway, I checked the publication you mention and all seems regular. Just a custom domain, once available on Medium but no more available (like other features) since Medium decided that publications are not particularly welcome (exceptions allowed…).