C# source file in ShooterGame?

Just browsing through the source files for ShooterGame on Mac and it seems that there are multiple CSharp (.cs) files scattered alongside the c++ files! Is ShooterGame partly written in CSharp or am I missing something obvious?

Those are build scripts used by UnrealBuildTool, Unreal’s custom build system (which is coded in C# too). Every UE4 project with C++ has them

Thanks for the answer! Will I need to familiarise myself with these scripts or will UE4 generate them automatically from what I have done in C++?

Yes, you will need to understand how they work, they are only auto-generated initially when you create a new project based on one of the templates in UnrealEd, then it’s up to you to maintain them.