How to answer a Product Design question in a Product Manager job interview

Product design interview questions evaluate your skills as a PM to discover users' unmet needs and your ability to translate those needs into innovative products and features. Product Design interview questions are meant to evaluate your ability to:
  • formulate a structured thinking process in an ambiguous environment,
  • find pain points in the customer journey that can translate into new products and features,
  • evaluate various use cases and focus on the ones that matter,
  • use your creativity and imagination to solve problems and to build new products that are practical and usable today,
  • estimate and take into consideration implementation efforts (which requires you to have a high level technical understanding).
Here is how you can answer a Product Design interview question:

1. Clarify the scope of the Project

This step is your chance to narrow down and clarify the scope of the question before you start designing your product. You want to be clear on the scope of the design task and get confirmation from the interviewer that they agree with your scope. Here are a few things you'd like to get clarity on:
  • Who is the user?
  • What do they want to do?
  • Why do they want to do it?
  • How do they do it?
Before starting to design a product, you also want to make sure that you and the interviewer are clear on the goal of your product design. You can ask the interviewer if they have a particular goal in mind or suggest one and ask for their feedback. For example, if the interviewer asks you to design an app for the Department of Motor Vehicle (DMV), you want to know if they are referring to a mobile app, Facebook app, or a web application. If the interviewer lets you make that decision, great! Either chose one path now to narrow down your options right away (and explain your reasoning behind it – e.g. I would chose mobile app because I think the web application has been around for a long time and there is probably more need for a good mobile app) or explain why you'll make that decision later (e.g. I want to think about the use cases before committing to a product form). Let's also assume in this example that the goal of the product is to reduce time spent at the DMV per visit.

2. List the user groups and chose the one you’re focusing on

Share your understanding of the different user groups that are part of the ecosystem of the problem you’re solving for. In the DMV example above, there are a few user groups that come to mind:
  • Citizens: people that contact the DMV to complete a task related to their cars or driving (e.g. renewing license, changing car ownership, etc).
  • DMV agents: they represent the DMV and help citizens complete their tasks. They are the bridge between the DMV and the citizens.
  • DMV officers: they look for violators of DMV laws and fine them.
  • Other DMV employees: They help run the DMV and are mostly behind the scenes.
You want to choose user groups that are distinct from each other and have unique needs. Explain the characteristics of each user group and what makes them unique briefly. After listing out the user groups, chose the one user group that you’ll be designing your product for and explain your reasoning behind it. For the DMV app example above, let's chose the citizens because they are a large group and given the goal of the product (reducing time spent at the DMV), they are motivated to adopt new changes.

Note that for steps 2 and 3, you can ask the interviewer if they can give you a minute to organize your thoughts about the user groups and their needs.

3. List the user needs for your user group

In this step of the answer, you want to provide a list of some the needs (at least five) of your user group relative to the product that you are designing. Continuing from the example above, here are a few user needs that come to mind:
  • When citizens visit the DMV they need to take a number to reserve a spot in the queue to speak with a DMV agent.
  • When it is their turn to speak with an agent, citizens will provide documents to identify themselves and submit an application form that they would have filled out earlier for their request.
  • They sometimes realize at the time of their visit that they are missing some documents and that they would need to come back another day to present the missing documents.
  • Citizens pay for the service they receive at the DMV with their credit cards.
  • They then wait a few days / weeks to receive their new documents / letters from the DMV.
A common mistake among PM candidates in step 3 is to start mixing user needs with solutions. It is very important to only cover user needs and not solutions at this step of your answer. For example, “waiting in the queue” is a user need. “Build a feature that lets you submit the reason for your visit and reserve a spot in the queue in advance” is a solution.

4. Prioritize the user needs

Once you have a list of user needs, you will want to prioritize them based on some meaningful attributes. Some examples are the impact to the user, revenue potential, and the level of effort to address that need.

You can go as far as creating a table that helps you evaluate each user need based on the criteria you have come up with. Summarize your evaluation and explain the reasoning behind choosing the 2-3 user needs you have selected.

Let's assume that I have done the analysis for the use cases listed above and I have chosen user needs 1, 3, and 5.

5. List your solutions

Step 5 is your opportunity to present your creativity and your ability to think outside the box by thinking about original ideas and innovative ways of meeting the prioritized user needs. When it's appropriate and the problem you're solving for allows it, I suggest you list at least two ideas that use new technologies that are trending (e.g. AI, Blockchain, AR, etc) as it shows your knowledge in the space and your ability to leverage the latest technological advances to make your product better. Even though your technology is leveraging new technologies, it is important to keep in mind that the interviewers would still like to see solutions that are practical and usable by the user.

At this stage, you can ask the interviewer for a minute to organize your thoughts and list out your solutions.

6. Evaluate your solutions

Your next step is to present your evaluation and execution skills by evaluating your solutions with different sets of criteria such as the impact on the customer experience, the frequency of usage, the impact on the business, implementation costs, and time to develop each solution. You can again use a table to make it easier for yourself to organize your thoughts and show your evaluation skills.

Next, prioritize your solutions based the results of your evaluation. As a product manager you are always dealing with trade-offs and different ideas proposed by various members of your company. A great product manager evaluates all ideas without any bias and develops a roadmap with the right set of priorities.

7. Summarize your answer

Wrap up your answer by briefly reviewing the goal of your product design, the user needs you focused on, and the solution you are recommending with some explanation on why your solution is good. This should not take longer than 1 minute.

I hope you found this article useful. I have gathered a list of product design job interview questions for you to practice.

See also

How to prepare for product manager job interviews

How to answer a Metrics question in a Product Manager job interview.

How to answer a Product Improvement question in a Product Manager job interview.

How to answer an Estimation question in a Product Manager job interview.

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