Long time since I did FORTRAN programming on this mainframe and on the Sperry Univac 1100/40, which later on took on the UNISYS name (which I like because it sounds a little like UNIVAC I knew just enough about EXEC 8 job control language to get by. Bye the way, even back in the early 1980’s these machines would still crash a lot. Later I programmed on IBM mainframes using VM/ESA OS which was a breeze compared to using EXEC 8. We used a 4GL software development tool called Application System released by IBM which was a real dog. I would have rather programmed in COBOL. I retired about the time the IBM equipment was hauled away and replaced by servers.
One more thing is that I read an article that said FORTRAN programmers are in demand to modify legacy systems at NASA. I am sure that there are a lot of competent FORTRAN programmers but my guess the vast majority are retired with no expertise on recent technology that is also required of an applicant. In my opinion, I feel these headhunters do not have a concept of the big picture.