Spotfire is an application for visual data analytics and it has been built upon .NET Framework 4.8. We wanted to run the web application on Linux and move to .NET 6, but with a lot of shared code that still needed to be consumed by a .NET Framework 4.8 application. How do you set up the projects in Visual Studio to support two frameworks at the same time? How do you handle all platform specific code and functionality? This is a real story from the real world, about a team's struggle and success when migrating from 4.8 to 6.0.