Currently, there are a few ways a user can connect products to Jira Cloud: application links, OAuth, DVCS or using apps available on our Marketplace.

There is, however, no warning when the same connection is being duplicated (e.g. you've integrated Jira Cloud and Bitbucket Data Center through an application tunnel and via OAuth as an app), and this can lead to duplicated information and possible problems with sync, as some products have issues with multiple connections.