I think both things can be true. These are valuable skills in some situations/jobs and you're selecting for students with these concepts still fresh in their minds and/or people who enjoy algorithm competitions.

And that's fine! A specialized subset of engineers. Maybe that subset is exactly what you need.

I wonder how the stress of the interview process selects out people who understand O-notation and to whom a Trie would make sense if explained to them, vs people who have these concepts fresh in their minds and/or can handle themselves in stressful interview situations.

The author, everyone.

You did emphasize it was the best result, so it's hard to argue that you selected for it.

Back in 2015 Peter Norvig discussed an analysis at Google that suggested doing well at coding contests was a negative indicator of job performance: https://youtu.be/DdmyUZCl75s

Presumably they do well at these sorts of questions, but that doesn't imply the same actual effectiveness.

If you watch the Peter Norvig link you shared on YouTube he actually interprets the phenomenon quite clearly: the statistic reported is only true for the subsample of people who get hired and absolutely not true for the general candidate population.

(Personally I would add that human measures of “job performance” can also be quite subjective.)

You're imagining I didn't listen to an extremely short clip of a talk that I linked to?

Yes, implicitly Google can only measure the job performance of people they actually hire.

I did not mean to imply you in particular did not watch it. The way this observation often gets quoted is extremely misleading (often intentionally so, as the first piece without the second is much more sensationalistic) and needs an explicit clarification, as Norvig did immediately after reporting the curious observation.

I am sure this person has NO IDEA how well the candidates do after they are hired.

What algorithms and data-structures do you commonly use when shutting down useful services?

LRU Cache

Perhaps there is a sort of selection bias going on, where the people who work at Google have been chosen because they are good at leetcode type problems and think they are important, and so they tend to solve problems by implementing their own tries and similar data structures, rather than by using robust canned implementations.

> rather than by using robust canned implementations

And who is supposed to implement the robust canned implementation?

Probably not a UWaterloo recent grad who is good at programming competitions and has just been hired onto a random product team at Google.

I’d posit that a UWaterloo grad who landed a job at Google is close to maximally likely to end up working on something like that [acknowledging that in absolute terms relatively few college grads do so.]

Would you care to extend your reply, and tell us how you use them? Just like you expect a good candidate to do ;)