In my experience, it’s the relatively basic questions that have the highest value — both because they’re what you run into programming most often, and because they’re less likely to overwhelm candidates in a high-stress setting.

The goal, at least from my point of view, isn’t to see if they can come up with the perfect algorithm, but about how they construct an algorithm, how they communicate about the decisions they’re making, how they respond to challenges about edge-cases, etc.

I’m also strongly in favour of picking out questions that are reflective of the actual codebase they’re being hired for — find something with some basic algorithmic complexity which has a relatively simple and easy to explain input and output, and use that as the problem.

In general, I think the best problems are those which any competent senior engineer could design a good solution for almost off the top of their head with little difficulty.

Then I had a technical interview when I was asked to implement a simple algo for the tris game (aka tic tac toe) and my mind was completely blurry.

I was tired, i'm in eu and this was for a San Francisco startup interviewing me at their lunch time, very late in Italy.

And generally don't like to be interviewed/tasked.

Of course the solution is beyond simple, but I struggled even at brute forcing it.

I can easily do these kind of exercises (and much harder ones obviously) for fun, but not when interviewed.

I struggled with the same thing in University. I graduated with 104/110 even though I was consistently among the most prepared, and I learned to learn, not to pass exams (plenty of stellar performers didn't remember anything few weeks after exams).

Once I asked a professor why did he grade me 27/30 even though I spent one hour answering with details on everything, including the hardest questions.

"Because you never appear convinced when you answer".

I get nervous, I don't like to prove my knowledge this way. I rethink constantly what I'm saying, or even how I sound.

I forget how to type braces or back ticks.

I did not have any issues when not interviewed, or in written exams, or during my research period when I published 3 papers that have been highly cited.

But I am just not a fan of these types of interviews they tell absolutely nothing about the candidate.

You interview me and you'll have the very wrong impression if you ask me to live code or white board.

Meanwhile I've seen leetcode black belts spend most of their time logged on Tekken 7 on discord, consistently creating work and providing negative value while somehow always selling their high skills.

I have found much more value in seeing personal projects, and OSS contributions.

Never asked a single of these bs questions and never failed at hiring anyone. Not once.