Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
Glitch is a collaborative programming environment that lives in your browser and deploys code as you type.
Progressive Web Apps (PWAs) are web apps built and enhanced with modern APIs to deliver enhanced capabilities, reliability, and installability while reaching anyone, anywhere, on any device, all with a single codebase.
Varnish is a reverse caching proxy.