[frumper]

No, the ideal interview is to ask them questions about what type of problems they've solved before and ask them to walk through what they did. Also, have a conversation with the person to get to know a little bit about what they're looking for in a job/company. It's an interview, not a tryout.

Metrics like a 10 minute task, or a 30 minute task is all relative. Do they know they language, the IDE, the operating system, the documentation, any experience in whatever abstract problem topic you choose, and personal comfort levels will all come into play.

If you want to filter someone to do a very specific thing then post to hire a contractor with the specifics of what you need. If you want a developer that can grow within your organization then pop quizzes area good way to dismiss good candidates.

[edanm]

> No, the ideal interview is to ask them questions about what type of problems they've solved before and ask them to walk through what they did.

This just doesn't work. Lots of people can bullshit very convincingly, and even if they can't produce novel solutions, can very well explain them in a matter that makes you think they for-sure know how to do it.

Hell, I can probably still prove lots of interesting things about set theory in math, as can many other people who studied math - doesn't make me the equivalent of the world-class mathematicians who actually came up with the proof.

Empirically, "talk to someone about what they did" doesn't give me hires that actually know what they're doing.