I'm from Central America. I went to SF and had a few interviews over a month. I failed in all those 40-minutes-solve-as-many-as-possible-fizzbuzz-problems because I wasn't fast enough.
That said, I've been working as a web developer for 11 years now, bulding CRM's, CMS', Crawlers, automation tools, and all kind of web based stuff companies needed.
Also, I never went to college, and have been working before finishing high school (15 years old).
So, while I lack a lot of computer science education, I consider myself competent at developing solutions, and have progressed with coding practices.
But because of the US interviewing style, which I had never gone throug before, I am not employable there. Interview Cake may be just what I need : )
It's tough out there. Most companies suck at finding candidates, and most candidates suck at finding employers. Very very few are doing the Matasano route of work samples and then measuring to make sure that this is actually working out.
We're a 70 employee B2B startup in NYC that uses something similar. We have a set of problems that we actually solved as we were building out the company - we now give them out as take home interview questions (different questions for different roles). Instead of brain teasers it's testing for real world coding abilities that apply to the job the person will be doing.
Assuming the code comes back ok we then use it as the basis for one of the interviews on site. I usually discuss design decisions and then make some changes to the requirements to see how they react.
We honestly haven't hired enough engineers to make any sort of statistical measure on it but anecdotally it seems to be effective. We've yet to end up with a false positive and I know that we've hired at least two engineers who are awesome that I don't think we would have hired based solely on an "algorithms at the whiteboard" interview. Plus our engineer-time-invested per declined candidate is way down. Rather than spending 60 - 90 minutes watching a candidate flounder at the whiteboard we can axe them in a 2 minute code review.