New visual aesthetic, what exactly do you mean? I did all the game gui development since 5.2; the global gui overhaul in 5.3 was sketched by Hagan. It's all written in Lua.
Yeah it's same for website, Hagan did some sketching and I made it work.
It's still same ancient version of vBulletin under the hood though, backend only got some minor tweaks to work with different setting grouping in user control panel and some other minor stuff.
I covered some more stuff in overhaul thread in news: https://forum.toribash.com/showthread.php?t=628013