My most recent assignment was to migrate an application of about 150 projects from the "old" still supporting .NET Framework 4.8 to the latest .NET 6. Since the application is still being developed and used, the migration should be done incrementally over time, in iterative steps rather than a big bang refactoring. This blog post will go into more detail on how I handled this situation and what I learned.
This is a very subjective article and there are many ways to achieve it - so take it with a grain of salt, results may vary.
application
The application itself is not that special - at least from a migration perspective. It's a typical 3-tier application with an Angular front end and a .NET Framework 4.8 back end. The backend is divided into projects, most of which are smaller tools such as console applications or library projects. Then there are two ASP.NET Core WebAPIs and some Windows Services done in TopShelf.
Task
As mentioned, the app is still in development - making a big bang is not a viable option. Even if no one is currently working on the application, it's still not a good approach in this case. So, I need a concept to iteratively transition from .NET Framework 4.8 to .NET 6. Best case: You have multiple JIRA tickets and can do these from time to time until the whole application is migrated.
Before going into details, we must clarify something very important: some terminology, as this will be important throughout the article.
.NET Standard/.NET Framework/.NET
We have to understand what these three different words are. Let's first look at Microsoft's official picture:
.NET Forward