I don’t know about the rest of the world but in Quebec calculus is not taught with any epsilon-delta formalism. You don’t encounter that until mathematical analysis, which is in the curriculum of a very few majors in uni.
"Best" schools (<1%) will have what the article is describing (strong student mathematical problem solving communities lead by teachers with strong mathematical training). Typically very expensive, either directly through tuition or indirectly because they are public schools but only serve students in very high net worth zip codes.
"Very Good" schools (<10%) will include some of the epsilon-delta formalism but might have some curricular problems and a "gifted just means moving through the terrible not-real-math curriculum faster" problem that the article talks about.
"Decent" schools will teach how to compute derivative/integrals by rote and maybe talk a bit about the physical intuitions in a very hand-wavy way. Calculus is very much a continuation of Algebra or Trig where you learn some rules and how to pattern match and don't ask too many questions about why.
The other half of USA high schools? They don't even offer a Calculus course of any kind [1]. Which... if you don't teach it at all, you can't teach it wrong...
As an aside, AP CS has the same problem as the problem identified with AP Calc. AP CS is the epitome of a "Java School" course.
[1] https://www.theatlantic.com/education/archive/2016/06/where-...
That's a bit misleading. There are many districts where one school serves as a magnet school where anyone interested in taking more advanced classes can go. So yes while it may be true that half of all schools don't offer calculus--far less than half of all students can't readily take calculus.
As a high school student who took AP CS last year, I agree, but in reality the course isn't even about Java. Code is written by hand on the free response portion and Java syntax is mentioned but not really emphasized (things like missing brackets and semicolons are okay on the FRQs). I finished all the questions in about 25 minutes, with over an hour left to twiddle my thumbs.
Even questions about algorithmic analysis (in APCS's case, just sorting algorithms) are done without proper big-O notations, which is just plain stupid IMO.
For a student that has done CS on their own for years now, APCS feels like the fake, industrialized, watered-down version.
All of the AP tests are roughly comparable in my opinion. Just not too many high school kids are as overprepared for the tests in chemistry, physics, statistics, economics, etc.
If you keep up your self-study, expect further disappointment in most undergrad data structures courses. =P
It's sad they killed it, it looks so fun.
[1]: http://mchs.virtualbeach.com/cs/documents/AP%20Computer%20Sc...
It's news to me that Stuyvesant considers zip code for admissions. I thought it was a standardized test open to all students in the system.