Thanks for your question in Microsoft QnA!
Unfortunately with ARM template there is no great tooling that will help! I will wait for someone else to post great tool.
Here is my recommendationa:
- Don't allow Manual changes, Put everything through GitHub Actions or Azure DevOps pipelines. https://learn.microsoft.com/en-us/devops/deliver/what-is-continuous-delivery
- For Initial deployment (since you already have infra) use What-if to determine what's changing.https://learn.microsoft.com/en-us/azure/azure-resource-manager/templates/deploy-what-if?tabs=azure-powershell
Use Deployment Stack for controled deployments : Use Deployment Stack : https://learn.microsoft.com/en-us/azure/azure-resource-manager/bicep/deployment-stacks?tabs=azure-powershell
Please click "Accept as Answer" if this helps