From memory when I worked there 10 years ago, all the Javascript based stuff was pretty slow in a very noticeable way. They've likely gotten better as they are using a well known Javascript and rendering engine, so they're getting many optimizations for free.
Flex247A · · focus · HN ↗
apaprocki · · focus · HN ↗
nxobject · · focus · HN ↗
I'd love to know how they make frontends as responsive as possible. To the engineering blog!
Scubabear68 · · focus · HN ↗