...these things were mostly written(and rewritten till perfection) on paper first and only the near-end program was input into a computer with a keyboard.
Not if you were working in a high-level language with an interpreter, REPL, etc. where you could write small units of code that were easily testable and then integrated into the larger whole.
Not if you were working in a high-level language with an interpreter, REPL, etc. where you could write small units of code that were easily testable and then integrated into the larger whole.
As with Lisp.
And Prolog.