Product Sense Interview: Tips From an Interviewer

Over the past month or so I’ve interviewed about 15 product management candidates. There’s a TON that has been written about how to prepare for such interviews; There’s an equal amount of unwritten information about how to conduct them.

All I’ll offer here is one interviewer’s thoughts on one particular (but popular) type of interview — the Product Sense exercise (a.k.a. product design). It is by no means the only type of exercise, nor is it a one-size-fits-all. It is, however, an important part of the suite of questions that an interviewer should know, and that interviewees should be prepared for.

What is Product Sense?

A Product Sense exercise is typically a 20–40 minute on-the-spot brainstorming session, in which the candidate is asked to develop a high-level design of a new product. They were popularized by Facebook and Google, and have recently replaced many of the 3-hour-but-actually-3-day home exercises.

Commonly, it might be one of two things:

1. a new feature for a familiar product (“Add a dog-walking marketplace to Facebook”, or “how would you improve Google Calendar?).
2. a special twist of a common product (“design a maps product for kids”).

The important thing that it should be general enough that it won’t require domain expertise, but specific enough so that you’re not just describing an existing popular product.

In this post, I’ll use the following exercise:

Design a traveling website designed for groups of friends

What’s great about these exercises is that they help the interviewer discover a lot about the candidate:

1. how do they approach a problem?
2. how methodological are they?
3. How do they collaborate?
4. how do they use their knowledge about the world?
5. How do they work under pressure?
6. How do they communicate and present their ideas?

Why you should use Product Sense questions

While you can definitely prepare for these questions, at the end of the day each question is different, so you can’t really “fake” it. Think about it as taking the SATs — preparing might improve your score from 1400 to 1500, but it will not make an 800-point candidate score a perfect 1600. (I realize the issues and criticism regarding the SATs. many will apply here as well).

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When it comes down to it, these exercises are good because that’s what we do as product managers. We’re given a problem, and we need to come up with possible solutions, analyze them, find relevant references, and collaborate with others. I actually started my current startup in much the same way. I was contacted by an organization that had knowledge management issues. While talking to them and understanding their needs, we very quickly came up with the concept for TagBox, first at a high level, then with first mockups a couple of days later. The result of those brainstorming sessions is astoundingly similar to our product today.

General approach and guidelines

To be clear: you’re not required to provide a detailed spec and design in 30 or so minutes. You are expected to discuss the issue and come up with a high-level possible solution.

The major downside of these exercises is that they put a lot of pressure on the candidate. Unlike home exercises that give you 2–3 days to come up with answers, you’re required to do so almost instantly.

The best way to get through them is to treat them as if you’re having a beer with a friend, and they start saying “so I have this awesome idea for an app”, and dish out a random thought, which you then go to develop together. When you think of it like that — these questions can become quite fun to do.

Another thing to remember is that it’s not the final answer that counts — it is exclusively the way you got there, the process you led, and your ability to manage and explain it.

Common pitfalls

Here are a few of the very common mistakes I’ve encountered over and over again.

1. Do not use up 90% of the time to describe what you would do. Instead, just do it. Many users will go on and on about how they would conduct interviews and why it’s important, and how they would research the existing solutions to the problem. These are product 101 answers, which are general, and do not tell me anything about you. Instead — go on and interview me as a customer. Ask the questions you would ask. If there are no answers, please assume, and explicitly state your assumptions.
2. Do not pass the design back to the interviewer. While we’re building this together, you should be the one leading the process. A good rule of thumb is that you should do about 80% of the work, and engage the interviewer for the remaining 20% of the time. It is okay to ask some of these, but you will need to make some decisions on your own.
   Example questions:
   - Should this be on web or mobile?
   - Should we sell flights? How do we connect to flight engines?
   - Is one person leading the purchase, or are they all together?
3. Be methodological. Do not jump from one idea to the next. This is probably the most common mistake of them all.
   Example randomness:
   - We should sell flights, definitely. I would interview a few customers and decide what’s important to them… Oh, and I need a KPI! Wait, we said we’re on mobile, right?

What you should definitely do

The best answers have a few things in common:

1. They narrow down the problem.
   “Okay, let’s take friends that are flying out for music festivals”
2. They find business value.
   “These groups can easily bring recurring business, and they might buy larger packages that include multiple buyers in one deal, getting flights, hotel rooms and tickets in one purchase”
3. They have a unique selling point, or a killer feature.
   “Let’s have each one connect their Spotify or specify their favorite artists, and we’ll find the best concerts that match all of the friends”
4. They think MVP
   “We can test this by putting up a website and where the ‘leader’ can add all the emails; We can then email them asking for their favorite bands, and manually look to find the best option for them, with suitable hotels and all. Hell, we can have this ready by next week!”

Summary

Product Sense questions are awesome, because, well, they test product sense, which is reasonably important for a product manager.

They are hard. Much harder than “tell me about your last job” or “how do you work with designers?”. But with the right attitude, they can be a lot of fun.

This post follows and elaborates on a Facebook post I wrote in an Israeli Product Management group, that sparked a heated discussion about Product Sense interviews. I’d love to continue the discussion in the comments below.

Also, don’t be stingy on the claps 👏 👏 👏, it helps with spreading this post around!

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