We have a requirement that we need to migrate the existing SharePoint 2010 OnPrem Farm solution into SPO. Please find the list of customizations and restrictions w.r.t environment.
Current O365 has single tenant model. For this model, we have 3 different site collections for Dev, QA and Prod. Can we have different app catalog site in single tenant model ? In this model, if we have only single APP Catalog, and developer upload the app in catalog, and QA found some bugs, even it is ready for install in Prod as well. How we can maintain the build/release management under this single tenant model. Please clarify.
Customer dont have provision of Azure / On Prem server to save the cost. For all customizations, we need to do through SharePoint Hosted app. Without having the option to host for provider hosted app(remote provisiong) how to implement the below artifacts using Sharepoint hosted app.
Custom Site Templates
Branding - Master pages, css, images, scripts
Provisioning List/ Document Libraries
Please clarify and guide me about how to proceed with solution design and architecture for the above requirements.