SharePoint is primarily written in C# [.NET Framework 4.8] and leverages ASP.NET; there would be no reason to rewrite the majority in another language. There is some C++ in SharePoint Search (and a few other components here and there).
IIS which SharePoint runs atop of is written in presumably primarily C.
You can decompile most of SharePoint if you ever need to peek at the code. That's a huge advantage to figure out how it works.
IIS which SharePoint runs atop of is written in presumably primarily C.
You can decompile most of SharePoint if you ever need to peek at the code. That's a huge advantage to figure out how it works.