Converting a Big Project to .NET Standard Without a Big Bang
See the original posting on DZone Python
When you have a big project in .NET full framework and you want to convert to .NET Standard/Core, usually MultiTargeting can be a viable solution to avoid a Big Bang conversion. You start with the very first assembly in the chain of dependency, the one that does not depend on any other assembly in the project. Then, you can check compatibility with .NET standard for all referenced NuGet Packages. Once the first project is done, you can proceed with the remaining steps in the process.
The very first step is converting all project files to new project format, leave all project to target full framework, then you can use a nice technique called MultiTargeting starting with the aforementioned first assembly of the chain.