Product Manager Interview: The Product Design Question

Product Manager Interview - Product Design Question

A product manager’s core job is to help design, build, ship, and improve a product so during product manager interviews, most companies love to question how a prospective candidate might think about designing a product.

The popular product design question usually takes shape in the form of something like:

Walk me through the steps of how you would design “X product” (there are many things I’ve tried asking; some common questions I’ve frequently heard include a pen for astronauts, an alarm clock for the blind, an elevator for handicapped individuals, etc…)

When you answer these types of product design questions, you should always approach them with a framework in mind. Below is one that I highly recommend:


1) Ask Clarifying Questions

Remember, there is no point continuing with an answer if you haven’t fully grasped the situation. I can’t count the number of times I’ve asked a simple product improvement question to a candidate who then proceeded to give me a lengthy 5 minute answer before I realized that the candidate had never used the product before. If I asked a candidate to walk me through how he/she might design a better wallet, I expect the candidate to first ask clarifying questions such as who the wallet might be used by, or what “better” means in the context of a wallet. Remember, product managers don’t just dive headfirst into launching a product without first understanding the whole situation and the business goals. A candidate who doesn’t ask clarifying questions is a big red flag and tells me that he/she would design products without understanding what a user truly needs.


2) Communicate Your Answer Outline

There is nothing worse for an interviewer than trying to follow a candidate’s unstructured train of thought when responding to a product question. It’s crucial to demonstrate that you have taken time to comprehend the situation and then lay out some groundwork on how you plan to answer this question. Showing that you are organized by structuring out your answers to these questions will put your interviewer at ease and keep your thoughts in line so that you don’t ramble or go off on tangents.

An example of how you might approach this is to say “Now that I’ve understood the scope of this product, I’d like to lay out how I might approach this design question. First, I’m going to re-iterate what my business goals are. Second, I’ll identify my customer base and their use cases. Third, I’m going to brainstorm some features and evaluate these features against the business goals I’ve listed. Lastly, I’ll discuss trade-offs and summarize my recommendation.”


3) Identify the Users / Customers and their Use Cases

Although you might have lightly touched upon this while asking some clarifying questions, this step is crucial to locking down exactly who the product’s customers and users are and their use cases. 

 Remember that for certain products, a customer may not necessarily be using the product. For example, the educational app/games market often has parents as the customers who are buying these apps for their children to use.

If it helps, I would recommend drawing a 2 column table on a whiteboard or piece of paper with your users/customers on the left column, and their respective use cases on the right column (users/customers may each have multiple use cases so leave some room on the right side to account for that). For example, going back to the better wallet, a user might be a working adult who uses a wallet to store their cash and critical cards (i.e. license, debit/credit cards/business cards). At this point, it would be great to ask more clarifying questions to your interviewer about whether or not they want to focus on a particular user/customer to save time.


4) Identify Gaps in the Use Cases

Now that you’ve compiled a list of various use cases, it’s time to start thinking about how current products/solutions in the market address these use cases and whether or not there are any gaps or room for improvement. Taking a step back, it’s good to look down your left column of users/customers and think about the qualities that are special to each one of them. Like a true product manager / customer advocate, put yourself in their shoes and think about their limitations and values. This will help you to better identify weak spots in current product offerings. If you want, you can add a third column next to each use case to help structure the obvious gaps that you locate.

5) Brainstorm Features / Improvements

So now that you’ve figured out the potential gaps that current products are missing to address user/customer needs, it’s time to break out that thinking cap and brainstorm solutions to address these gaps. Make sure that your features / improvements match the use cases that you’ve listed and don’t be afraid to ask your interviewer if you are on the right track or if they prefer you to focus on one or two of your ideas.


6) Prioritize and Identify Trade-offs 

With this new shiny list of features and improvements that you’ve come up with, it’s time to prioritize which of these you might focus on and what the trade-offs would be with each solution. When you prioritize your ideas, it’s important to use some sort of structure. If you are focusing on business goals like revenue, it might be important to use prioritization framework such as considering revenue generated, time / cost to develop. One simple way is to take the (potential revenue generated – cost to develop ) / time to develop and first prioritizing your list this way. Otherwise, you can also prioritize off other variables like customer satisfaction depending on what your goals are.

Once you’ve come up with this list, think about the pros/cons and trade-offs of choosing to implement each solution. This lets you automatically play devil’s advocate to your own ideas to show your interviewer that you are thinking about all facets of the solution including edge cases and potential negatives. As an interviewer, I love to see candidates critically think about their own ideas and tell me the trade-offs vs. requiring me to grill them.


7) Summarize your Recommendation

Whew, you’re almost done! Let your interviewer know what your final choice is and feel free to review how you came to the solution and why it satisfies a user / customer’s needs. If you haven’t elaborated enough already, feel free to reiterate why you chose this solution over the others on your brainstormed list. Congratulations, you’ve finished your first product design question!

Interested in learning how to dominate these types of product manager interview questions and land the product manager job? You might want to check out our popular course: One Week PM


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