Hi @haidong Welcome to the community! I'm sorry to hear that you're running into this issue Retool should be auto-saving quite frequently.
Are there any patterns you've noticed (i.e. specific actions that don't seem to save)
Using the release management feature might be helpful.
I'm not sure how helpful this would be if it's not saving in the first place, but it might be helpful to try using the ?_historyOffset=1 parameter at the end of your URL. This will allow you to "travel back in time" 1 step. You can increase the number to go further back in time if you still don't see the app data. The idea here is to go back to the most recent version so you don't have to redo as much work. ***WARNING!*** If you make any changes to the canvas when traveling back in time, that past version will become your present version and it messes with the history, so be careful not to touch anything! Once you find a version that you'd like to make that your present version, then you can make an edit to the canvas (move a component, add a component, etc) to persist that view.