You are not the fastest at solving programming puzzles. Does that mean you're not smart? No.

Personally I think you are one of many who overvalue the importance of solving technical problems quickly. Quoting a Google analysis from two years ago at http://www.nytimes.com/2013/06/20/business/in-head-hunting-b... :

> Years ago, we did a study to determine whether anyone at Google is particularly good at hiring. We looked at tens of thousands of interviews, and everyone who had done the interviews and what they scored the candidate, and how that person ultimately performed in their job. We found zero relationship. It’s a complete random mess, except for one guy who was highly predictive because he only interviewed people for a very specialized area, where he happened to be the world’s leading expert.

It sucks that you didn't get the job you want. Don't conclude that you are not smart because of it. Throw your rationalization out the window - by analogy, chess playing computers are all about "rote learning skills", and they play better chess then pretty much every human. It's all too easy to be caught up in the idea that hard work isn't as important as some sort of innate genius.

See also http://www.kolotv.com/home/headlines/Praise-That-Backfires-W... which is one of many pieces (https://www.khanacademy.org/about/blog/post/95208400815/the-... is another) on how praise for smartness can backfire. Eg:

> In Dweck's research, she split kids into two groups. As one group solved puzzles, her team would tell the kids they were smart upon completing the task. She found that these kids started to avoid doing anything tougher. ...

> "If you try hard, it's almost like, 'Oh, you just really didn't have the talent to do it,'" said Barone.

> With sports, it's accepted that being the best means practicing. But if the brain is a muscle, just like your body, why is the body praised for going through the struggle, and the other, stigmatized?

> "In the U.S., struggle is seen by kids -- we've studied this -- as something that makes them feel incompetent," said Dweck. "They think, if you're really really smart or talented, it should come easily."

Most of the TC like problems seem to be about quickly associating the problem with an already known algo/s and adjusting it to fit the problem? I did Informatics Olympiads in middle school. The people that did well seemed to basically memorize TAOCP or Cormen.

The next level up seems to be problems that require composing algorithms. This type of problem takes creativity, some insight into how to combine, for example, graph algorithms with dynamic programming to come up with "optimal" solutions. These are quite hard for me, especially dynamic programming - it seems to be a favored component in many problems.

Maybe consider downloading 5 or 10 years worth of ACM programming contest problems. Take your time, work through each one, and add to a notebook (or even something like Anki) for regular review.

There is a book on competitive programming at https://sites.google.com/site/stevenhalim/ The first edition is freely available there as a pdf.

Stepping away from your question, you mention that your puzzle solving speed is holding you back from getting your desired job. This is a tough situation - it sounds like the job you want is at a company where these puzzle interviews are prized. If it is possible, maybe you could try to create some working sample code that addresses the job requirements. A portfolio you could put forward and talk about with interviewers instead?

I sometimes try to think from the perspective of how would I setup a course to teach someone to be good at some specific subject. Occasionally I even manage to do that and turn around and make myself the student in that course. You've got a PhD already, so determination isn't a problem for you. Keep grinding!