So far, we’ve been developing locally by turning our own computers into a server that we access using the localhost:8080 URL. Running locally is a good habit to get into, because you want to test your changes before you unveil them to the entire world. But if you want other people to be able to visit your web app, you have to host your server somewhere.
This is a companion discussion topic for the original entry at https://happycoding.io/tutorials/java-server/hosting-google-app-engine