This document discusses new approaches for customizing site provisioning in SharePoint Online. It provides a brief history of site provisioning techniques and introduces themes, site scripts, and site designs as the current preferred approach. Site scripts allow automating common provisioning tasks while site designs facilitate reusing site scripts across multiple sites. The document demonstrates how to create site scripts and designs with PowerShell and extend provisioning by triggering Azure Functions from site scripts. It recommends learning more about these declarative customization techniques going forward.