I´m curious about how the timestamp in the URL gets updated as the video plays. Is the server sending GET requests every second?
1 Answer
The only way I could think of is the history API.
https://developer.mozilla.org/en-US/docs/Web/API/History_API#Adding_and_modifying_history_entries
It's often used by single page applications (SPAs) to implement routing, so if you use browser controls to reload or move back and forth, you get more or less to the same state as before.