[pjmlp]

It appears to me that the issue was not being confortable with the .NET eco-system.

Roslyn and RyuJIT aren't the same thing. Roslyn is the new compiler infrastructure for MSIL generation, where the original C++ compiler got replaced by bootstraped VB.NET and C# compilers.

RyuJIT is the new JIT compiler introduced in .NET 4.6, replacing the former JIT64.

I don't disagree that Julia is better suited for data science given the eco-system, as proven by my other posts in this thread, just that the performace is also there when one wants it.