If you’ve ever stared at a classic ASP.NET application running on aging on-premises servers and wondered, “How do we ever move this to the cloud without rewriting everything?”—you’re not alone. At Microsoft Ignite 2025, Scott Hunter (VP, Product Management), Gaurav Seth, and Andrew Westgarth delivered a technical session on Managed Instance on Azure App Service, a new capability that lets you lift-and-shift Windows-dependent apps to PaaS with minimal code changes.
Let’s get into it…
Migration isn’t just technical—it’s organizational. IT folks know the infrastructure inside out but often don’t understand the application’s behavior. Developers know the app but struggle with server roles, registry settings, and file system dependencies.
When the app is third-party or built by a long-gone vendor, the challenge multiplies: no source code access, zero internal knowledge, and no easy way to modify behavior.
Common roadblocks include:
- Complex application dependencies (COM components, third-party DLLs)
- Hard-coded local/network file paths
- Registry settings
- In-process session state
- Reduced permissions in PaaS environments
- Long migration timelines with delayed ROI
The result? Many organizations stay stuck on IaaS VMs, paying for management overhead they no longer want.
Managed InstanceS on Azure App Service
Now available on Premium v4 plans, Managed Instance gives you a dedicated, container-based Windows environment inside Azure App Service—think “VM-like flexibility with PaaS simplicity.”
Key Capabilities That Solve Migration Challenges
- Bring Your Dependencies Run a custom installation script at deployment time to install anything your app needs—COM objects, third-party runtimes, even desktop apps.
- Persistent File Access Mount Azure Files or Blob Storage as local drives. No more rewriting file I/O code.
- Registry? No Problem Use Registry Adapters backed by Azure Key Vault Secrets. Your app reads the Windows registry exactly as before, but values are securely stored in Key Vault.
- Full Troubleshooting Access Connect via Azure Bastion for RDP-like access. Run ProcMon, check event logs, and debug just like on-premises.
- Automatic Scale & Maintenance Enjoy App Service autoscaling, patching, and high availability—without managing VMs.
- AI-Ready from Day One Seamlessly call Azure OpenAI, integrate Cognitive Services, or modernize parts of your app with GitHub Copilot.
How It Fits into the Modernization Journey
Managed Instance is now a highlighted path inside GitHub Copilot app modernization (formerly GitHub Copilot for Azure). Pair it with:
- End-to-end portfolio assessment (Azure Migrate + CAST)
- Automatic .NET Framework → .NET Core upgrades
- Containerization assistant for Dockerfiles
- PostgreSQL modernization extensions
The result? Move faster to PaaS, cut operational costs, strengthen security, and light up AI experiences—all without a massive rewrite.
Final Thought
Managed Instance on Azure App Service isn’t just another migration tool—it’s the bridge that finally lets us retire those old VMs, reduce costs, and start adding real value with AI. Whether you’re moving one stubborn app or an entire portfolio, this is the fastest path to modern Azure.
#Azure #AppService #DotNet #CloudMigration #Ignite2025
