Author: Jose Zarazua

  • I’m a former CTO. Here is the 15 sec coding test I used to instantly filter out 50% of unqualified applicants.

    I’m a former CTO. Here is the 15 sec coding test I used to instantly filter out 50% of unqualified applicants.

    If you have a remote position open, your challenge is not attracting the correct candidate, it’s filtering out the bad ones, because you’ll have hundreds or thousands of them.

    This my favorite technique:
    Add a programming knockout question to the application process that is so simple to solve that only* unqualified developers will not do it manually.

    Here’s the question:

    result = 0
    for x in [3,3,5]:
        if x >= 3:
            result = result - x
        else:
            result = result + x
    

    What is result?

    1 0
    -11 -10
    Reveal the answer

    If you got 1, congratulations, you have wired your brain to easily interpret code.

    If you got -11, you copy pasted it somewhere. The trick is that there’s a hidden equal sign in the conditional “if x > 3”

    The logic of course is that for a good programmer it would be more of a hassle to copy, open an interpreter or ChatGPT, paste it, run it, then answer, than just run the code in their head.

    I used a very similar question while I was CTO at MonetizeMore. Interesting things happened:

    50% of candidates got the AI/Interpreter answer.

    47% Answered the question correctly.

    3% Answered incorrectly.

    A few candidates resubmitted the application after getting the answer wrong (we didn’t tell them), one of those candidates was a great hire.

    One candidate posted the incorrect question to a forum, and got an answer. So when subsequent candidates Googled the incorrect question, they got the wrong answer.

    *I should say this method is not perfect, and you’ll get false negatives, but I see it more as doubling your ability to process candidates, or reducing in half your recruitment time.