Work for mgr who's never heard of Joel Spolsky?

Not a red flag - Joel was much more at the forefront of "tech pop culture" a decade ago than he is now. So your potential manager may just be younger, which is not a red flag. Or maybe he was busy 10-15 years ago and didn't keep up on blogs. Also not a red flag.

I'm a big fan of reading Joel Spolsky's essays. Usually when I should be grading papers, or something like that, and decide to procrastinate instead.

Perhaps your interviewer is better at resisting procrastination than me? (I should be polishing off a grant proposal now as I write this, but here I am commenting on HN instead..)

Some positions may require an extensive knowledge of who's who and what the trends are in the industry, but I would guess a technical position is not one of them.

Not a red flag, in my opinion.

Not a big deal at all. I'm sure the manager can name drop 10 other people, like book authors, the interviewee never heard of.

No. Some people don’t follow the pop culture of hackers, but are still solid coders.

No.

Not a flag, red, green or otherwise.

I'm not accusing you of doing this, but some people that are well versed in the cultural hacker scene constantly play out an obnoxious variation of this in the form of:

"You've never heard of X? Really? C'mon, X, the inventor of Y?"

It does not endear them to their colleagues.

I'm happy to talk about figures in computing with anyone else who shares a similar interest, but I make zero correlation of their competencies whether they know of a certain figure or not.

Nope. The only red flag I can see here is with the interviewee thinking this might be a red flag.

Been in tech for 3 decades. Use Stack Overflow almost daily. Embarrassed to admit I've never before heard of Joel Spolsky.

Hope you didn't take the job.

Saves them a lot of pain in the ass.

If you decide it is a red flag, it is a red flag.

That's how red flags work.

Anyway some red flags say "uneven pavement."

Some say "bridge out."

How you treat each of them depends on what you are driving, where you are going, and why you are going there.

Good luck.

In my opinion, Verity Stob wrote a much better essay on Unicode than Joel Spolsky

https://www.theregister.com/2013/10/04/verity_stob_unicode/

Does the interviewee know about Verity Stop?

I think that is just as much of a red flag as not knowing about Joel Spolskly (pretty much none)

On the other hand, if you don't know about Donald Knuth (at least heard the name) I would be concerned.

I mean, Joel Spolsky is just like, some guy. Even Paul Graham is not exactly noteworthy in computer science or software engineering, except to a relatively small cadre of engineers that want to build startups (there are about 27 million software engineers in the world). Plus there's always new blood coming in that have never heard of who you think is important and might have learned via a completely different pathway.

No red flag in terms of a bad manager; red flag that reflects poorly on an interviewee who is strange enough to think that something like this matters.