I worked with a guy like this. He told me this story to impress me with how incisive he is. Instead it told me he is an egomaniac. His story went something like this, I don't recall the exact details:

"I was interviewing a candidate who said he had experience programming on an IBM/370. So I asked him if you perform a character edit format instruction in EBCDIC mode with the leading zero specifier and the numeric value is too great to fit into the allocated field, after the instruction completes, what is the state of the program status word overflow field?" Then trounced the guy for not knowing. The thing is the guy asking the question happened to have worked on that instruction when he worked at Amdahl.

One thing to know is the IBM 360 and descendant family had a commercial instruction set option that, in a single instruction, could take a format value and generate a string output that followed some format specification, kind of like sprintf but with even more options.