If you're looking for the US Homepage you'll be sorely disappointed to know that it's not here!
The Home Page for the US as well as the other 'Marketing' pages exist in another software repo called pb-marketing-site-websiteui-us. That separate application is a separate SPA (Single Page App) which uses React, Redux, Webpack and TypeScript.
If you want to work on the marketing pages, go clone the repo mentioned above.
We stitch the sites together with Azure App Gateway which routes request to the correct applications depending on the route requested. It's like magic! Only it isn't.