We here at Webflow went through great lengths to implement the command pattern in our web designer. It has definitely paid off when we tell our users they can j

We here at Webflow went through great lengths to implement the command pattern in our web designer. It has definitely paid off when we tell our users they can just hit Cmd+Z and Cmd+Shift+Z anytime they make a mistake. That said, it's really difficult for webapps to fully support undo/redo. A lot of the web is transactional, and different actions trigger follow on actions. GMail does a really good job with its undo, but there's a reason it goes away after 10, 15 seconds!