When building your interface we encourage you to save frequently. What you see in the builder is called the 'Working Draft'
You can save your changes by clicking 'Save' in the top right hand corner of the builder interface. This will save the 'Working Draft'.
Once you're happy with your changes and the way your interface is working, you will likely want to publish it so that your users can see the changes. To do this, click 'Publish' in the top right hand corner. This will open the 'Release Management' panel.
The release management panel shows a timeline of all the releases that you have published for this interface. The working draft is always displayed at the top of the timeline, followed by all existing releases in order of most recently published.
Each release can be marked as a 'milestone' which would indicate that the release is stable and appropriate for your customers to start using. You can toggle the milestone property on a release at any time which can be useful for rolling back releases. Applications can be created and configured to use different interface releases, allowing you control and flexibility for creating development, staging, production and preview environments.
On the right hand side of the Release Management window, you can write a commit message describing what changes you've made that you are releasing and then press 'Publish'. If you select 'Production Ready' the release will be published as a milestone.