I've known about hyperfiddle for a while, but I never really "got" it. I finally get it, this is https://glitch.com but with a hosted database and can be used for real web apps in production, thanks to datomic's use of data for schema migrations instead of imperative sql style migrations and datomic's support for "time travel".

It's definitely a huge leap forward for productivity, seeing as you can throw away git, your text editor, bash/ansible/puppet/docker/k8s for deploys since you're editing things live on datomic cloud, but it's a hard sell, even to a huge clojure fan like me, I'm just so used to the status quo.