How to Answer Product Design Questions

Why are Product Design Questions asked?

Interviewers like to ask Product Design Interview Questions as a way to evaluate your ability to:

  • Formulate a structured thinking process in an ambiguous environment.
  • Find and evaluate pain points in the customer journey.
  • Use your creativity and imagination to come up with solutions to build new products that are practical and usable today.
  • Estimate implementation efforts and cost.

How to answer Product Design Questions?

Here is a step by step guide/framework, you should follow while answering product design interview questions:

1. Ask clarifying Questions to narrow the scope. (Q)

2. Define the Goal you want to achieve. (G)

3. List the User Segments and choose one segment to focus on. (U)

4. List and prioritize the Pain Points. (P)

5. List out your Solutions. (S)

6. Evaluate the solutions and prioritize them. (E)

7. Walk through the MVP & Define the Success Metrics (M)

8. Summarize your answer (S)

(PQGUPSEMS) -> Mnemonic to help you remember the steps & their order.


Now, let’s go through each of the above points and understand them in details,


Step 1. Clarify the scope of the question

Before your start designing the product, it is important to clarify and narrow down the scope of the question 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?

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, or a web application. If the interviewer lets you make that decision, great! Either choose one path now to narrow down your options right away and explain your reasoning behind it (e.g. I would choose a 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).


Step 2: Define the Goal you want to achieve.

Before starting to design a product, 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 or metrics in mind or suggest one and ask for their feedback.

Example: Let’s also assume in this example that the goal of the product is to reduce time spent at the DMV per visit.


Step 3: List the User Segments and choose one segment to focus on

At this step, list down the different user groups that are part of the ecosystem of the problem you’re solving for.

User groups should be distinct from each other and have unique characteristics.

In the DMV example above, here are a few user segments:

  • Citizens: people that contact the DMV to complete a task related to their cars or driving (e.g. renewing a 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.

After listing out the user groups, choose 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.

Feel free to ask for a minute to think about the use cases before giving an answer.


Step 4: List and prioritize the User Pain Points.

In this step of the answer, provide a list of some of the needs of the selected user group relative to the product that you are designing.

Continuing from the example above, here are a few user needs:

  • 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.

Note: Remember not to mix pain points with solutions. You are still not solving it at this stage.

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.

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


Step 5: List out your Solutions

This 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. It is important to keep in mind that the interviewers would 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.

Toufiq Mahmud