Tech interviews are 40 minutes max? Where are you interviewing?

I have seen far more 6+ hour interview loops that 40 minute ones.

Maybe each session within the full loop accounts for 40 minutes.

That being said, people have their pet questions they use to sort the wheat from the chaff--if you can't fizzbuzz your way out of a wet paper bag, I am not hiring you. The best questions are more about process than the final answer. Solve an easyish problem, add some features, add some more features. What other ways could you have solved that problem? Why did you choose this way? When would you use a different approach? How does your solution scale?

The worst questions are gotcha questions with a right and wrong answer, `what does the C99 standard indicate is the correct size of a stack frame?`