[catchmeifyoucan]

I wonder if they're still using Electron under the hood or not.

Ah seems like they're using WebView2 (based on MS Edge)

https://techcommunity.microsoft.com/t5/microsoft-teams-blog/...

[schemescape]

Yeah, it’s still a Chrome-based web view, just now it uses a shared library instead of essentially shipping an entire extra Chrome via Electron.