It's true, answering all of those questions has greatly improved my skills in a demonstrable way, but it also signals that I have those skills, which means I probably won't be asked to demonstrate them in situations where others would. It could be used as a heuristic that at least gets me a free pass not to take the "can he code fizz-buzz" question. Then the question is, "can he architect a continuous integration system in a maintainable sort of way?"
If you're in the top 3% of Python users on SO, Fizzbuzz should take you no more than, so optimizing against that doesn't seem particularly useful.
And it feels to me like being able to cogently answer questions on StackOverflow isn't a skill that's necessarily correlated with architecting big systems. The value I'd imagine you have, out of this skillset, is being able to explain your code to other developers, give good code reviews, figure out new systems, etc.
If it were me, I'd mention it on my resume and give it some wording in the hopes that an interviewer will ask me questions along those lines and ask me to explain some code and I'll do a good job of it. But that would also be selecting for jobs where my work does involve a lot of working with other coders and doing code review, and not speak very much to my ability to do architecture and design review.
(Or maybe I have the wrong impression of what all this is about, and you should take me as an example of a naive interviewer and correct for that. :) )
