Can you point me in the right direction for information on integrating a new CMS? I've got a graphql API (that can be tweaked if needed) that I'm confident I can get working with the query playground (looks like GraphiQL).

Specifically I'm wondering about the mechanism for pushing content updates from the CMS. Is there a webhook or something to notify Web Studio that there is a new item in a collection? Or does Web Studio fetch each collection periodically for updates? Or does Web Studio fetch the collection from the external CMS every time it needs it (so it is always fresh)? ...I have questions like this.

Thanks for your help. Any additional resources would be great.
-Stefan