This post has been republished via RSS; it originally appeared at: Microsoft Developer Blogs.Happy Friday! This is the last post for this month - and it's been a good month. I hope you've had time to check out some of the sessions from build via the Microsoft Build page. If you haven't, it's not too late to find something to watch. I'm still catching up on sessions. Now, on to stories covering container-based builds, ARM templates, UI testing, build variable management, and the Power Platform, from you - the wonderful Azure DevOps community! Docker performance on Azure Pipelines agents David has done some testing about the experience with container-based builds. Some good information to consider and an option for caching if you use Linux containers. ARM Template what-if deployment Nice post from Barbara exploring the new "what if" capability in Azure Resource Manager template deployment. She walks through the new capability and shows how it can be used in side our Azure Pipelines builds. Automated GUI Testing of UWP Apps Using Appium and Azure DevOps Chun Lin joins us with a guide for setting up Appium testing for UWP apps in Azure DevOps. Backup your Azure DevOps variable groups to a Git repo Knowing what variables influence your build and deployment process at different points in time can be critical in debugging or troubleshooting. Vassili shows us an interesting technique to back up variable group details into a git repo. Power Apps Build Tools for Azure DevOps Gets Updated with Service Principal Connection and Default SDK Versions I think Power Apps and the Power Platform are pretty awesome. Colin recaps some of the latest updates in Power Apps development with Azure Pipelines. If you’ve written an article about Azure DevOps or find some great content about DevOps on Azure, please share it with the #AzureDevOps hashtag on Twitter!