Working on the university main frame computers, it would take a number of hours of run time to test each building block much less the full program at once. One of the guys on my team was also taking a computer science class and had learned enough Assembler to add a few lines of code that tilted our access to CPU time so as to reduce our turn around time. Cool! BTW, the 4 teams in that class racked up greater CPU usage than the computer science department as a whole.
That was the last time I wrote FORTRAN code. Logical and generic command tricks I picked up on, I have used off and on over the years to create simplified simulations using spreadsheet software as the framework. First Lotus 123, then Quatro Pro and lastly Excel. It usually drives a spreadsheet bonkers since it thinks there are circular errors when you are working loops to a convergence or other loopy things. Dumb software sometimes but it works.
I learned on Fortran, switched to Basic when the class got a new system. Had to learn JAVA to teach a course in AP computer science. Had to learn assembler at Lockheed Martin because one of our subcontractors used it to build a telemetry system. All in all it was a good series of jobs. Had experience on cobol, algol, and VHDL (not technically a software language).
When I got to the part where we taught the history of computers here in Silicon Valley, I realized that I actually used each of the machines as they became the latest and greatest. I recall Voyager too, I believe it carried a record of earth and human designs and a map of quasars that pointed to our star.