Legacy WPF applications often contain years of valuable business logic, hidden rules, and workflows that cannot simply be rewritten over a weekend. The safer path is to modernize one valuable slice at a time while the application continues to serve the business.

In this demo-driven session, I’ll show how to select a low-risk workflow seam, define what behavior must remain unchanged, and introduce Blazor into an existing WPF application through `BlazorWebView`. I’ll replace one legacy screen while keeping the rest of the desktop application running around it.

GitHub Copilot will help assess the existing code, uncover dependencies, scaffold the Blazor component, connect shared services, and generate tests. We’ll compare the old and new workflows, verify behavioral parity, and use clear rollback boundaries so the modernized slice can be reversed without disrupting the rest of the application.

You’ll leave with a practical modernization pattern that delivers visible progress without a big-bang rewrite, a frozen feature backlog, or years of waiting for the new system to arrive.

Takeaways
- Select the safest workflow seam to modernize first.
- Run WPF and Blazor together during migration.
- Preserve behavior with parity checks and rollback paths.