Typescript makes VSCode very slow though. I remember the feeling when switched from Atom to VSCode it's wicked fast. And then Typescript happens, my macbook's fan keeps spinning from time to time.
I think they mean the performance of VSCode editing a project with Typescript code in it. There's the runtime cost of VSCode checking the Typescript, providing intellisense, etc. (Not that I've ever had that runtime cost be noticeable to me. Maybe it's a real issue on certain codebases or workflows.)
