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My experience like this was for a data scientist position at Facebook in 2022.

So the question was something like, here is a table of predicted probabilities for credit card transactions (hypothetical table, I do not remember the exact quantities), but it looked something like this:

    Amount, Probability, ActualFraud
       $5 ,    0.2     ,  0
     $100 ,    0.5     ,  0
       $3 ,    0.7     ,  1
       $1 ,    0.9     ,  1

And then the question was "what was the threshold used to maximize (precision|recall)?" (I cannot remember which metric they were asking for).

My response was that a proper decision model should take the dollar amount of the transaction into consideration, so the decision should more like be `$*p > threshold`, where this threshold meets your precision and recall for preventing dollars lost instead of the binary yes/no.

The interviewers English was not great, so after all that I was just like "well to answer your exact question, it could be anywhere between `0.5 < p <= 0.7`"

Did not make the second round!

2 comments

At one point earlier in my career (during the early 2000s), they flew me to Chicago, picked me up in a limo and gave me a tour of the office... I knew I didn't want to relocate (from the East Coast) and remote work wasn't an option back then, so I had nothing to lose... They asked me the question of "4 lightbulbs in a room down the hallway, with 3 light switches in the room I'm in" to tell which switch belonged to which bulb...

I went in totally unprepared for logical tests, and flubbed the perfect answer partially, but it was funny because I asked the guy if I was "doing an interview to be an electrician or a software developer?".

Since then I've been just fine, and to this day, I've never had to answer that question nor use that type of logic on any job... I reverse engineer & migrate major software apps all the time as a Solutions Architect & Development Director.

I've always found interviews that involve behavioral and cognitive tests to never be good for me as long-term jobs... Now I interview & hire people regularly without asking those types of questions at all because the questions can too easily be studied & rehearsed prior to interviews.

A common interviewer mistake is looking for exact answers, assuming that a candidate just needs to regurgitate facts.