I see

https://msdn.microsoft.com/EN-US/library/office/jj692554.aspx I can create development site in office 365. if I create QA site collection and UAT site collection side by side how deployment in dev affects QA an

Hi,

In SharePoint online, developer site collection, QA site collection and UAT site collection are separate.

Developer site collection is able to develop SharePoint Add-ins. And you could publish add-ins to public Office Store to make add-ins acquired by users of any SharePoint deployment. Or you could publish add-ins to an internal organization add-in catalog make them available to users with access to that SharePoint deployment.

About how to set up a development environment for SharePoint Add-ins on an Office 365 Developer Site for your reference:

https://msdn.microsoft.com/en-us/library/office/fp179924.aspx

About publishing SharePoint add-ins:

https://msdn.microsoft.com/en-us/library/office/jj164070.aspx

Best Regards,

Dean Wang