Partly cribbed from my comment downthread: I think I'd classify Knuth as the slightly different "longest working computer scientist". He's known for his quote "Beware of bugs in the above code; I have only proved it correct, not tried it."

Or perhaps I'd classify him as the somewhat more sycophantic "longest working genius" or "longest working cool guy". Heck, Knuth was uniquely awarded a master's degree for his bachelor's because his work was considered so outstanding, he's an organist and composer, and he's hilarious. I love this quote about him: "If you had an optimization function that was in some way a combination of warmth and depth, Don would be it."

A quote from him in an interview I found: "Indeed, as mentioned above, my life's work was to be a teacher."

That's the way he likes to paint himself. From a lecture he gave at my university I remember that he said something along the lines of, that he usually came up with the idea and others wrote the code. From the experience out of the same lecture, however, I can tell you first hand that he knows his way around code and that he can code. The lecture was indeed more of a hands on workshop with Knuth spending most of the time in Emacs coding MMIXAL assembly - pretty low level stuff actually.

Oh I have absolutely no doubt that Knuth can code better than I (or most people in this thread) ever hope to.

But being a programmer and a computer scientist -are- two very different things. Simply in his daily activities over the last sixty years, Knuth has been writing tens of thousands of pages, doing a lot of math, diving deep into computer science topics. (That is not what I do in my employment as a programmer.) This guy has been sitting behind a keyboard and writing code. (That is what I do.)

Just because he can code doesn't mean he does on a daily basis for a day job, which is what this ask hn post is about no?

Knuth still does code basically on a daily basis. At least that's what he said in some interview (writing two complete programs per week on average, small and large, and that definitely qualifies him as software engineer among other things) and I have no reason to doubt it.

https://www-cs-faculty.stanford.edu/~knuth/programs.html

Arguably, TAoCP has been his day job since the 60's, and it's full of code.

Anil Nerode is almost surely the oldest working computer scientist today - https://math.cornell.edu/anil-nerode - He technically is in the math department at Cornell but he has been there since well before Cornell had a computer science department.

I just read his CV. He got his PhD under Gödel. He was at Princeton when Einstein was still there. Amazing!

To be honest, it's a bit weird to judge a man on the basis of a joke he made over 40 years ago.

Now, I certainly wouldn't judge someone based on an out of comment snippet from nearly a half century ago, but Knuth has been portraying himself in a less-programmery, more CS-and-teacher-y way for forever, including interviews from last year. And I think he's being honest - that is who he is.

But being a programmer and a computer scientist -are- two very different things. Simply in his daily activities over the last sixty years, Knuth has been writing tens of thousands of pages, doing a lot of math, diving deep into computer science topics. (That is not what I do in my employment as a programmer.) This guy has been sitting behind a keyboard and writing code. (That is what I do.)