To support this approach of programmatically creating artifacts, a lot of work is being done on the "Provisioning Engine" in the OfficeDev Patterns and Practices Library on GitHub. To put it very simply, the Provisioning Engine reads a predefined XML file called the "PnP Provisioning Schema" and creates all the SharePoint artifacts using CSOM. Since this engine predominantly uses C#/.NET, it is expected to be run from somewhere like an Azure Web Job, a Web Application on an IIS server or a simple console application.
This method of provisioning is great for clients who opt for Azure subscriptions or IIS servers along with their SharePoint roll-outs. But this is not necessarily true with clients who only want to go for SharePoint or who do not have enough budget for additional Azure or IIS installs. So far, the only option in these cases is to go with the traditional declarative XML based provisioning using No Code Sandbox Solutions (NCSS). This approach is still valid at this time and Microsoft has stated that No Code Sandbox Solutions continue to remain supported:
Some code examples from the project:
1) Create Site Column:
2) Create Content Type:
Here are my observations about this approach:
3) This approach can be used to create sub sites but not site collections as there is no way right now to create site collections through JSOM. So the deployment process will have to be manual creation of a Site Collection with an empty web template, and then to upload the WSP which will deploy the JS file to the SharePoint site. This file will then do the artifact provisioning.
I am going to explore these options and will post something in the future around this approach.
Thanks for reading. Hope you find this information useful in some way!