Our entire JS is 800kb not each page. So we are splitting it on a per page basis. Everything including issues, MRs, file browsing. There was 800kb of JS in the entire app before I joined as the first FE Eng. There is jQuery and other libraries and our own code. That was the reason we wanted to remove Turbolinks. So we don't load all the JS for the entire app at once. We want to load things on demand.

Funny thing, I have built a full fledged production 2d/3d application in JS. It was less complex than what GL has to do, and it was 670kb fully minified and obfuscated. We are constantly looking for ways at GL to make our file size smaller and our JS faster. It is something we are actively putting our time towards.