Writing a domain-specific language on Racket is kinda Racket's main selling point. If you don't trust me, you can trust the people who made Arc and HN. Afterall back in 2007 you had other options. Some of them vastly popular even now (Rails, Django, PHP, Scala, ...).

I don't think HN News uses Arc anymore. Also Arc is just a language written with racket. Racket is a language for making languages.

By the way, we'd be interested to hear how your deployment is going, what versions you're using, etc. Feel free to drop me or Matthew a line anytime.

Arc has many design decisions that are different than Racket, so Arc reimplements a lot of parts.