His approach is actually correct (well, aside from doing it in the browser). I wrote a custom, fully from scratch Vulkan UI rendering engine, works more or less exactly as described above. Crazy efficient and performant. Removing VSync I can hit ~100k fps on a dingy 4 year old GPU. For instance in benchmarking opening a window is a _sub microsecond action_. Doing the same in Qt is what... milliseconds? Literally? Also all of the things you described is because... browsers are bad. Or people are incompetent. Drawing fonts is a single draw call and yes, you can and should cache absolutely anything. All the fonts I used are 100% cached. Oh and btw it isn't a toy UI framework but fully production ready.