The web apps are super interesting. Its light and fast. On par with the desktop client. Meanwhile, Facebook Messenger takes eons to load, Discord's web client's initial load will hog up my CPU. It will be interesting to see the technology behind this.
"vanilla javascript" usually refers to something like manipulating the DOM directly, without using frameworks, transpiled languages and similar. Both of them seems to be using a bunch of different tech, from typescript to wasm, jsx and more, not sure I'd call that vanilla javascript.
On a second note, I'm surprised that both the new web versions are so similar. Seems just a couple of margins changed and other minor changes (profile picture filling the background vs being a centered circle for example), but built differently. Wonder if they both worked towards the same design maybe?
i think both of them are not using any framework, one of them uses an inhouse library which resembles react but overall i would say it's pretty vanilla (as in no frontend frameworks)
You might be right in the first half, but TypeScript (which they seem to be built in mostly) is not vanilla JavaScript, no matter what library or frameworks you use.