Additional examples of WebAssembly being used at scale that I haven't seen others mention yet:

Microsoft - https://www.microsoft.com/en-us/garage/wall-of-fame/calc-ts-...

Adobe - https://medium.com/adobetech/acrobat-on-the-web-powered-by-w...

Fastly - https://www.fastly.com/blog/announcing-lucet-fastly-native-w...