The era of the .csproj is over: How Microsoft Just Simplified C# Forever

The post says .NET 10 adds file-based apps for running a single C# file directly from the terminal. It removes the need to create a .csproj, bin, or obj structure for small scripts and prototypes, while keeping the code fully compiled and JIT-optimized.

It also says the workflow stays open for growth, because dotnet project convert app.cs can scaffold a complete project from the file when the script becomes larger.

Reading notes

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• Run a single C# file with dotnet run app.cs or dotnet app.cs.
• No .csproj, bin, or obj folders are needed for this file-based workflow.
• The code is still compiled and JIT-optimized, not interpreted like the older .csx format.
• dotnet project convert app.cs turns file-level directives into a proper .csproj.
• The change removes scaffolding for quick scripts and prototypes while keeping a path to a full project.