C coding... I am not a software engineer, I am an HPC engineer which sits a bit also on some grey areas of the software engineers and many other parts of High Performance Computing (HPC).

I have learned C, C++, Java and others I don't recall now. But after reading many languages you sort of start understand lots of things. Later in life I have learned a bit for Fortran, HTML, PHP, python, shell scrips, and others.