Product Case Interviews Dos and Don’ts for Data Scientists

product case Feb 14, 2023

Product case interviews can be a tough nut to crack. They require both technical and non-technical skills which means you have to be at your best in both areas to ace them.

In this blog, we will go over the dos (tips) and don’ts (red flags) of product case interviews. Knowing these can help you put your best foot forward while also avoiding some big errors.


Let’s start with the positives. Here are 5 tips for product case interviews.

It’s Okay to Make Mistakes

Making a mistake in an interview can feel like the end of the world. However, it is not the end of the world or even the end of your chances at the job if you make a mistake.

If you start to discuss something and realize it doesn’t make sense, the best thing to do is just admit it. That’s far better than continuing to pursue a bad answer.

Of course, you can’t make mistakes constantly and have to correct yourself on every question and still expect to pass the interview, but one or two mistakes will not kill your chances.

Quality Is More Important than Quantity

You do not need to provide as many ideas as you can possibly think of for each question. It’s better to provide solid suggestions that you can discuss clearly than to try to wow the interviewer with how many ideas you can think of.

Typically, 3 ideas per question are enough.

Interact with the Interviewer

The one goal of the entire interview is to convince the interviewer to give you a yes on the job. You need to make sure that they fully understand you and are engaged during the interview.

How do you accomplish this though?

You can start by sharing multiple ideas and asking the interviewer what they want to hear more about. Then, when explaining your ideas, remember to check in with the interviewer often. Ask them if it makes sense and if they want more details.

Checking in with the interviewer ensures that your answers are always on topic and to the point.

Always Clarify Questions

Always make sure you fully understand the question before answering!

Clarifying questions means asking the interviewer to confirm things like how a business defines a certain metric, the goal of a feature or product, how a feature works, what data is available, etc.

Sometimes the interviewer may seem reluctant to answer your questions. They may ask what you think. In this case, you should explain your understanding of the question and your assumptions and ask the interviewer if working with those for this question makes sense.

Remember that do not want to ask obvious questions - questions that you can easily find answers to online. This would indicate that you have done very little preparation or research on the company. Don’t ask what the company’s main product is, but it’s fine to confirm your understanding of specific features.

Take Time to Structure Your Answer

Don’t be afraid to take some time to plan your answer before you start. It is completely acceptable to ask the interviewer for a couple of minutes to write things down and structure your answer.

Ideally, you want to stick to less than 3 minutes for this, but you can take more time. Don’t start talking until you have an idea that you feel comfortable talking about.

What if you never get an idea though? If it’s taking more than 5 minutes to come up with something, you likely need more training and practice before your interview. If you prepared well, you will have ideas.

Red Flags

Now that you know some things you should do in interviews, let’s talk about some things you should avoid.

You Have No Idea

The biggest red flag is that you have no answer at all.

This does not mean that you don’t have ideas the second you get the question. As we already discussed, it’s fine to ask clarifying questions and to take some time to think and write things down.

However, if after a few minutes, you are unable to come up with anything, that is a big problem and often means you need to do more preparation.

Now, I know for some people the problem is not actually preparation but nerves. You get so nervous that you struggle to come up with answers. If you’re that type of person I have two tips:

  1. Remember that an interview is a conversation. The more you treat it like a normal conversation the more at ease you will be.
  2. Practice more. Mock interviews are a great way to make yourself more comfortable with the interview setting.

You Have Too Many Ideas

We all know that having no ideas is bad in an interview, but did you know that having too many ideas is also a red flag?

Sharing too many ideas is bad for a few reasons.

  • It can make you sound random.
  • It can overwhelm the interviewer.
  • You don’t have room to show depth to your ideas.

For these reasons, quality over quantity is always best. You can offer the interviewer multiple options but then ask about which one they want to hear more about before diving in.

You Follow a Framework Blindly

Never make it obvious that you are following a framework.

Frameworks can be helpful, but there are also generic. They are general outlines for answering types of questions not for answering specific questions.

When answering a question always make sure that you consider the context and adjust your answer to that information instead of sticking to the framework. Each answer should be unique, and you should be okay with getting away from your general structure if the question requires it.

You Cannot Defend Yourself

Not being able to defend yourself means that you cannot answer follow-up questions, you are clearly unsure about your ideas, or you frequently change your argument.

Any of these are bad because it indicates that you haven’t thought your answers through. Make sure that you can explain the reasoning behind your answers so that you can answer any questions the interviewer asks with confidence.

In Conclusion

If you find that you are making some of these mistakes or that you are not doing some of these tips, the best way to fix that is to practice.

Practice is crucial for sounding confident and capable in interviews, and mock interviews allow you to learn your strengths and weaknesses before the real thing. I highly recommend doing several mock interviews to prepare.

If you’re interested in learning more, check out this two-part blog post about acing product case interviews (Part 1 and Part 2).

Also, there’s a longer version of this post with more detailed examples that you can check out here.

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