Knowing what to ask in an interview is tough. There are so many interesting things you could ask, but the truth is, hardly any of them will actually help you figure out who the best candidate is.

I’ve hired hundreds of people for all kinds of roles over the years. That said, if I could only use one interview question from this day forward, I know exactly what I would choose.

The Single Best Interview Question

“What project are you most proud of in your career?”

Don’t be fooled by how simple it sounds because this question is incredibly powerful. The way a candidate answers it will immediately tell you what matters to them and what they care about—and when it comes to hiring, that information can be so much more important than having a long list of qualifications and experience.

When I’m interviewing people myself, the most important thing I screen for is a good fit for the role. I need to know if this person will thrive in the position or simply tolerate it.

I ask myself questions like:

Will this person love the bad parts of the job just as much as the good parts?

Does it play to their strengths or require them to focus on things that are a heavier lift for them?

Are they truly a nice fit for this role—and is it also a nice fit for them?

If you already know that someone will bring their very best efforts to work every day, stay engaged, and stick around, it can make all the difference in the world when looking to hire. But you can’t just ask someone if they’re the right fit—because odds are they’re going to say yes either way. At the end of the day, we all go into interviews looking to make a good impression, so it’s not uncommon for people to stretch a “no” into a “maybe” or a “maybe” into a “yes.”

That’s why the “What project are you most proud of in your career” question is so great, because it lets you sidestep some of the more generic or socially desirable interview responses and gives you a chance to get a sense of the real person instead. When candidates start talking about what work project they’re most proud of, what they’re really telling you is what they value.

For instance, let’s say you were interviewing a call center candidate and they immediately answered this question by talking about a project in which they were able to develop a creative response that not only helped the team handle difficult customers but also ended up being useful for turning a handful of those customers into loyal brand advocates on the same call.

These are the kinds of people you want to have on your team because being proud of a project like that shows how much they care—and it’s a great sign that they’ll do really well. Anyone can have the technical skills to be great at a job, but it’s not really the same if they don’t enjoy or value it. Thus, if you want top performers, you need to find the hidden gems who have both the skills and the passion for the work.

The Key to Making this Interview Question Work

Let’s say you’ve got a promising candidate and want to make sure they’re truly a solid fit. Fortunately, you can easily expand on the first question by asking tons of follow-ups. This gives you a chance to dig a bit deeper and see how the candidate responds to a variety of situations.

You can start by asking a lot of clarifying questions that’ll give you a better sense of the full project, such as:

  • How long did it take?
  • Were there any metrics or goals that you achieved?
  • Who else was involved? What were their roles?
  • What was your exact responsibility and ownership?
  • What was the overall purpose of this project? How did it play into the bigger picture of the company’s objectives?

Intricate answers to follow-up questions will give you a sense of how complicated the project was and how much of its success actually came down to them—which is good to know because it’s possible that they might be riding on the coattails of another colleague’s success. Similarly, asking follow-up questions will also help you cut through the kind of fluff where someone might be making a project out to be a bigger deal than it actually was.

After those are out of the way, that’s when you can get into the really juicy stuff—like what their biggest challenge during the project was. This will give you a much fuller picture of their role in the project, as well as how they respond to something unexpected. (It’s often easier to talk about something that had a great end result rather than the mistakes or setbacks along the way.) You want to look for signs that someone is proactive, creative, and dedicated to finding a way around a problem.

Some of my other tried-and-true follow-ups include:

  • Can you tell me more about that?
  • What did you mean by X?
  • Can you go into more detail on Y?
  • It sounds like you’re saying Z. Am I getting that right? Is there any more to it?

It’s all about demonstrating genuine curiosity and engaging with what they have to say. While some interviews can feel like both sides are just ticking boxes, questions like these can make interviews feel much more conversational and rich, giving you far more useful information.

One thing to remember is to be quiet and listen after you ask a question. Give candidates enough space to unpack their answers, and don’t jump in to fill silences. You’ll often get the most interesting information after sitting there in silence for a few moments.

Great Signs for Call Center Candidates

This interview question can work well for hiring in all sorts of industries, but if you’re looking for call center candidates specifically, there are a few things you should keep in mind when listening to their answers.

Great call center candidates will:

Choose a customer-facing project

Working with clients is the core of any call center job, so your ideal candidate will tell you about a project that was customer-facing in some way. It doesn’t have to involve work from a call center specifically, but it should center around customers. If they tell you about a project that was done purely on the backend, involved a lot of research, or was done mostly in isolation, they may not be the best fit.

Demonstrate their proactivity with customers

The best call center workers are creative, innovative, and empathetic. Look for stories where the candidate had to use some out-of-the-box thinking to deliver an exceptional customer experience. The more they’re able to show you how they can think on their feet to surprise and delight a client, the better.

Be aware of their own boundaries

You want to make sure that the people you hire are clearly aware of their roles and boundaries at work. Going above and beyond is great, but you also don’t want an agent going rogue or promising things they can’t deliver. Whatever story your candidate shares with you should demonstrate that they know when they’ve got some wiggle room and when they need to get approval for something spontaneous. You may have to do some extra digging with follow-ups to get at this particular element.

Show a clear passion for learning the business

Great call center agents aren’t just cogs in a bigger machine; they actually understand what they’re doing and how they play into the bigger picture. The more the agent understands the business, the better they’ll be at their job—and the more motivated and engaged they’ll remain when things get hard. If a candidate’s answers show dedication to the team over themselves, that can be a great sign.