How can you tell a novice from an expert?

Of course there are many ways.

But one simple test I like to use, for example when interviewing developers or engineers for technical roles, is a simple question:

What is your least favorite thing about your favorite [programming language/cloud provider/some other tool]?

I like this question because it very quickly and easily helps separate the novice from the expert—even if I don’t understand their answer.

It’s important to ask about their favorite tool. This avoids the problem that practically everyone can think of a criticism of some tool they’ve barely used, if only “it’s confusing to me.”

Everyone has a favorite tool. But a novice’s favorite may have a difficult time articulating why. Often this enthusiasm has a lot more to do with familiarity than with actual affection for the thing.

Someone who’s only ever used, say, Java, often won’t have enough perspective to formulate a criticism. They likely don’t know the different options offered by Python, Ruby, or Haskell.

In contrast, an expert is much more likely to have consciously bumped into the boundaries inherent in their favorite tool.