Spec is very useful, but please implement it without macros. Metosin did a great job to make it more usable, but we still struggle because specs could only exist in Namespaces. We want to use spec as EDN with pure functions. (+ recursive specs would be awesome)
Yup, Svelte is hot and Postgres is always a good decision! Thank you for the details, really interesting project!
Once I built a CSS based browser MMO myself as a challenge. I used Clojurescript and React on the front end and Clojure with a simple in memory key-value storage. My solution was basically a turn based architecture, but many turns happened in a sec, so it was semi-realtime.
CSS means I didnt use webgl, just pseudo 3D with divs and transforms. Field of view was small, but playable. :D
Clojure's startup time is very slow compared to other languages, but we balance it with fully reloadable systems both on the backend or frontend.
Otherwise the speed is almost identical to the speed of native Java and native Javascript.
Except when you experience the power of lazy structures, then Clojure is faster than native code.