Electron, iirc, is just the UI layer. Atom actually has a lot of code written to render, edit, and rerender text (they were initially using React at one layer of the process). I can't find it now, but there was a good blog post from the Atom team that discussed their efforts in detail. So I guess I'm trying to say that I believe the code handling the slow parts is predominantly unrelated to the UI layer. Also, iirc, VSCode's editor is based on Monaco (http://www.zdnet.com/article/microsofts-browser-based-dev-to...).