Recently I had a conversation with a colleague who told me a story of an interview he failed that left me thinking about how a company can fail the interviews they are doing.

The coding challenge

We were having a conversation about database locking (if you don’t know or care about what this is, don’t worry, it is not important to the story). We were debugging an issue that was created by something called deadlock and he mentioned that one time he failed an interview because, at that time, didn’t know what database locking was.

In that interview, for a non-senior developer role, the interviewer asked him to implement a system that would count the number of likes for a given article. It seemed simple enough.

He coded a solution and the interviewer pointed out that the way he had built it, it was possible for two requests to try and up the likes counter at the same time and lose one of those updates.

The interviewer asked my colleague why that could happen and how he could avoid it, he hadn’t considered that scenario and he didn’t know the mechanism to avoid it so he didn’t provide a correct answer. The interview ended and he didn’t pass because of that.

What’s the problem with that?

I think that that was a terrible interview question. Or, I should say, the way it was framed was terrible.

The situation described during the interview is likely to happen in the real job and, if it did, it would be expected that the person would be able to understand it, there’s nothing wrong with it.

The reason I think it was framed in a terrible way is that I presume, given the way not having a correct answer was handled, the question was solely asked to check if candidates would have a hard time dealing with that particular topic. If they did, they failed the interview, if they didn’t, they passed it. It is a very simplistic way to approach an interview and a huge wasted opportunity to evaluate the candidate’s potential with more nuance.

Why the interviewer failed the interview

Is it wrong to fail a candidate because they don’t know one particular concept? Well, it depends.

If the candidate didn’t know a key concept for the role they are applying for, especially for a senior role, then I’d say that failing them would be appropriate because that would indicate that they don’t have enough experience in the area if they didn’t have to deal with issues related to it.

But my colleague was interviewing for a non-senior developer role! Not knowing a particular concept shouldn’t be a deal-breaker, especially if the interviewers didn’t take the time to evaluate how he would be able to navigate through a problem he hadn’t seen before and learn from it!

The missed opportunities

They missed a great opportunity to have a conversation with the candidate and understand how he would handle a similar situation in a real job. Concepts that are new to them will continue to come up day after day and what is valuable to evaluate is how they will handle those situations instead of knowing if they are familiar with a particular concept because that doesn’t tell you how they deal with unknowns.

The interviewer failed at the interview because they made candidates go through a technical interview for no real reason, with no intention of having a conversation and getting to know the candidate. They could’ve just asked them to explain was a particular concept was and be done with it.

Conclusion

This is a great example of how to approach technical interviews and how interviewers can choose the intention of the interview. Don’t approach interviews with a binary mindset and be ready to delve into it, embracing nuance.