No, I haven't, but I've used apps coded in Assembly and boy were they ever fast! Even networked using serial cables on 286 processors running graphic simulators, they were amazingly fast!
My first coding was some mainframe 101 basic (I forget the company) in college. But I have gui business database apps still accounting for, and taking in thousands of dollars daily, after 20+ years in operation. ;-)
(That isn't me in the picture, BTW. I worked in a "Blue" building - if you're familiar with the term - and neatness was the order of the day; no beards, no long hair, shirt and tie...sigh). It's kind of why I loved becoming a SysAdmin later on in my career when I could get rid of that attire. :-)
Blue building: All equipment and software IBM owned and managed.