I have been a gfortran developer/maintainer for over 10 years. I am most familier with the runtime libarry internals of gfortran. I implemented the runtime portions of the User Defined Derived Type I/O. I am implemented significantt parts of Namelist and formatted I/O. I have contributed several intrinsic procedures and have fixed over 600 bugs/features at least the last time I attempted to count. I implemented a signficant portion of optimized matrix multiplication intrinsics.
I do understand some portions of the front-end portions of the gfortran compiler such as the parsing, some checking, and to a lesser extent the “translation” code.
I am a Licenssed Professional Engineer in the State of Washington (USA) and have been employed in the instrumentation and control systems engineering field for over 30 years with experiance in nuclear, chemical, and patroleum industries.