My last project as an intern was to rewrite an old batch processed COBOL app into a simple webform in C#/ASP.Net. The COBOL app was nothing special, really. From what I recall, it was around 65 pages printed. Took me a while to comprehend what was going on, but the first 80% or so was basically just hard-coded rules to take action on based upon user input. Things like when "B", generate "X" & "Y". When "A", generate "X", "Y" & "Z" sort of thing. Nothing fancy, at all. Once I figured out what was going on, I basically just ran the COBOL through some regexs, transformed into an XML doc (don't judge me - it was early 2000s) and wrote the rules engine in maybe one or two screenfuls of C#.

I did learn one thing, and that was COBOL has one up on 'goto'. Check out the control flow statement: MOVE NEXT SENTENCE. It's basically a goto, but it doesn't jump to a label, per se. Instead, it jumps to the next period in the source. Yes, in a big, blocky, verbose language like COBOL, where everything is in UPPER CASE, you're now looking for a teeny tiny period that is easily lost in the verbiage. Hands down, my least favorite programming language construct ever.