10 PM product design interview questions (with sample answer)

Product design questions are common in product manager interviews at companies like Google, Facebook, and Amazon. In fact, they made up 13% of the 600+ interview questions that we collected from these three companies.

So we’ve put together a list of product design questions, such as "How would you design a phone for deaf people?" along with pointers on how to answer them.

First, we’ll dive deep into a framework that will help you answer all product design questions, as well as a complete sample answer that uses that framework. If you’d like to skip straight to the list of questions, you can here.

Let's get started.

1. How to answer product design questions

We recommend using a three-step approach to answer product design questions in a product manager interview. This approach is also known as the BUS framework:

    1. Business objective
    2. User problems
    3. Solutions

    If you're preparing for a product manager interview, we strongly encourage you to learn that framework, as it can also be used for product improvement questions (e.g. "How would you improve YouTube?"). Let's go through each of the three steps one by one.

    How to answer product design questions?

    Step one: Business objective

    Many candidates skip this step and start listing design ideas in an unstructured way. This is a big red flag for interviewers. Here are the things you need to do before starting to think about user problems and how to solve them:

    • Outline your answer
    • Define the business objective

    First, you should lay out your approach to solving the question. You could say something like, "First, I'm going to try to understand the business situation and our objective in more detail. Second, I will focus on defining the target user and brainstorming what problems we could solve for them. And third, I will generate solutions for these problems, prioritize them, and make a recommendation."

    Outlining your answer shows you've got strong communication skills. If you jump straight in and answer the question in an unstructured way, it will be very hard for your interviewer to keep up with you.

    Second, you need to clarify the business situation and objective. Knowing the business context and what it's trying to achieve will help you make better design decisions later on. This is particularly important if the question your interviewer asks is vague.

    For instance, let's imagine your interviewer wants you to "Design a phone." Then you might want to ask what is the specific business objective we are trying to fulfill (e.g. sell as many phones as possible with a low price point, go for the premium market, etc.); and if we already have a user in mind for the phone (e.g. business users, teenagers, etc.).

    You'll design completely different phones depending on the answer to these questions.

    Step two: User problems

    Now that you know more about the business situation and objectives, it's time to think about the users and their problems in greater detail. Here are the things you need to do in that step:

    • Select a user type
    • List user problems
    • Prioritize user problems

    First, you should identify the different types of users for your product, and you should select one to focus on.

    Going back to our phone example, with the business objective to focus on an underserved market, you could suggest focusing on: deaf users, visually impaired users, elderly users, users with mobility issues, etc. List these different users and select one with your interviewer.

    Note that you can skip this part of the discussion if your interviewer has already specified a type of user they want to focus on in their initial question.

    It's also helpful to remember that for some products, the user and the customer are not the same person. For example, that's the case for games that parents buy for their kids, or software (e.g. Jira) that managers buy for people in their teams.

    Second, once you've got a target user, you should think through what problems you can solve for them. An easy way to do this is to imagine them using the existing product or service you're trying to replace.

    For instance, let's imagine we are focusing on deaf users. What are the problems they are facing with current phones? Here are some examples: 1) can't hear the phone ringing, 2) can't hear the other person talking on the line, 3) can't listen to voicemails, 4) can't hear app notifications, 5) can't hear the sound on videos received from friends, etc.

    Third, you should prioritize one to three items from the list of problems you have created. It's common to prioritize based on how painful that problem is for the user. For instance, you could say something like, "My suggestion is to focus on solving problems one and two because those are the two features that really define a phone and they are currently inaccessible to deaf people."

    Step three: Solutions

    Once you've defined the user problems you are trying to solve, it's time to generate some solutions. Here's how to do it:

    • List solutions
    • Prioritize solutions
    • Summarize

    First, for each of the user problems you have identified, you should generate potential solutions.

    Let's do this for user problem 1: deaf users can't hear their phone ringing. You could build a phone that does any of the following things when ringing: rings for longer than standard phones to give more time to pick up, flashes bright colors on the screen, vibrates really strongly, is connected to a vibrating wristband / watch, sends visual notifications to other connected devices such as laptops, TVs, connected light bulbs, etc.

    At this stage it's helpful to draw a table with two columns on a piece of paper or on a whiteboard. The first column should contain the user problems you have decided to focus on. The second column should contain solutions to solve each problem.

    Second, once you've generated a few ideas, it's time to prioritize the ones you will recommend building. A common way of doing this is to grade each solution from 1 (low) to 3 (high) based on how much value they would deliver for the user, and how easy they are to implement.

    You will need to do this for each of the user problems that you identified in step 2. Don’t forget to address the trade-offs of your solution (e.g. a vibrating wristband would require users to pay for additional hardware).

    Finally, after going through that exercise, it's a great idea to state the initial question again, and summarize what product you suggest building and why. This summary is a simple way of telling your interviewer that you are done answering the question. And again, it's an efficient way of showing you've got great communication skills.

    Mistakes to avoid when answering design questions

    There are two common mistakes candidates make when answering product design questions that you can easily avoid.

    First, a lot of candidates simply skip step one and start answering the question without first agreeing with their interviewer on a clear objective or target user. As mentioned above, this is a red flag.

    Second, many candidates don't spend enough time selecting a single target user and creating a short list of user problems. In other words, they start working on step three too soon. The more work you do in steps one and two, the easier brainstorming and selecting solutions will become.

    2. Example: Design a computer keyboard

    Now that you know what approach to use to answer product design questions, let's apply it to a full example.

    Try answering the question below following the BUS method we have described. Play both the role of the interviewer and candidate, and make decisions regarding what business objective and target user to focus on.

    Try this question:
    Design a computer keyboard
    Answer:

    1. Business objective

    Let's start by outlining the approach we are going to take. First, we will discuss the business objective. Second, we will analyze users and the problems we could solve for them. And third, we will look into solutions and make a recommendation.

    Here are the questions that immediately come to mind to clarify the business objective for this design question:

    • What's the business objective? Maximize profits? Focus on an underserved niche?
    • Do we already have a target user in mind, or is that something we should explore / discuss?
    • Keyboards are often paired with a mouse. Do we just want to design a keyboard, or should we also design a mouse that goes with it?

    Let's assume here that the interviewer wants us to design a keyboard for gamers but isn't interested in the mouse, and that the business objective is to maximize revenues.

    2. User problems

    Now that the business objective is clearer, let's start thinking about users and user problems in more detail.

    There are different types of gamers we could focus on. An easy way to segment them is to split the market between casual and professional gamers. Given we want to maximize revenues, it makes sense to focus on casual gamers, as it's likely to be a much bigger market than the professional segment.

    Let's now brainstorm typical problems casual gamers face when using standard computer keyboards:

    1. User can't perform at their best because keys are slow to respond, collect dust underneath over time, and aren’t easy to replace
    2. User can't easily create personalized shortcuts, as the software available to customize the keyboard is rudimentary
    3. User has to replace keyboard frequently as keys that are repetitively used wear out / break (e.g. space, shift, etc.)
    4. User is distracted by noisy keys
    5. User can't easily turn the game volume up / down from the keyboard
    6. User can't see keyboard keys when playing in the dark
    7. User's wrists / hands hurt, as keyboard is uncomfortable to use for long periods of time
    8. Etc.

      Let's now prioritize these problems by putting ourselves in the shoes of a gamer. Most gamers' primary objective is probably to win at the game they play. As a result it makes sense to prioritize solving problems, which will help users significantly improve their performance.

      Let's therefore focus on problems one and two, as these look like they could make the user faster and better if solved.

      3. Solutions

      Let's generate solutions now that we have selected a type of user (casual gamers) and a set of user problems (one and two above).

      We'll rate the solutions from 1 to 3 directly inline. For technical simplicity, we'll give 1 to the hardest solutions to implement, and 3 to the easiest. For value delivered to the user, we'll give 1 to the least valuable solutions and 3 to the most valuable. And then we’ll add up both numbers.

      Here are some solutions which could help solve problem one:

      1. Build keys that don't need to be pressed as hard / deep for the user input to be registered (Simplicity = 3, Value = 3, Total = 6)
      2. Build keys which register user input quicker thanks to alternative technologies (e.g. magnetic keys, mechanical keys, etc.) (S = 1, V = 3, T = 4)
      3. Build keys that can easily be removed to clean the keyboard or that don't let dust settle under the key caps (S = 2, V =2, T = 4)

        Here are some solutions which could help solve problem two:

          1. Create software that lets users define different sets of shortcuts depending on what game they play (Simplicity = 2, Value = 3, Total = 5)
          2. Create software that makes automated suggestions for shortcuts based on commonly used shortcuts by other players with similar keyboards (S = 1, Value = 2, T = 3)
          3. Create software that lets users adjust how hard / deep they need to press the keys for their input to be registered (S = 1, V = 3, T = 4)
          4. Add additional buttons to the keyboard that let users generate a combination of keystrokes (i.e. a "macro") in a single keystroke (S = 3, V = 3, T = 6)

            Now that we have generated some solutions, let's prioritize them based on how easy they are to implement and how much value they bring to the user. 

            For problem one, it therefore looks like prioritizing solution a) makes sense. One of the tradeoffs to bear in mind when implementing that solution is that we could make the keys so sensitive that the user might inadvertently press the wrong keys more often. We will therefore have to balance sensitivity and control of the keyboard.

            And for problem two, solutions a) and d) are promising options. Here, an important tradeoff is balancing customization and complexity. We're targeting casual gamers, so we want to give them a good level of customization, but not make installing and personalizing the keyboard too complex and lengthy.

            Finally, let's summarize. Our recommendation is to build a keyboard for casual gamers, as this is most likely to maximize revenues. We also recommend building features that will help the user maximize their performance, while remaining simple to implement. Here are the three features to build:

            • Keys which are more sensitive than standard
            • Software that lets the user create shortcuts
            • Additional buttons for "macro" shortcuts

            3. 10 product design interview questions

            Now that you’ve seen a framework to answer product design questions as well as a sample answer that illustrates it, let’s get into some other questions that you can use to practice. 

            Below, we’ve listed ten product design interview questions that were asked in PM interviews at Google and Facebook according to data from Glassdoor.com.

            For each question, we’ve included a few bullets and jumping-off points to consider as you craft your answers. You’ll find important questions and clarification points under each Business objective, three possible pain points under User problems, and three possible solutions under Solutions.

            Of course, these lists are not exhaustive, and you should add your own insight as you work through them. They’re designed to get your wheels turning and offer some hints if you’re stuck. If you'd like to learn about the other types of questions you may face, you can also visit our ultimate guide to product manager interview questions.

            1. Design a pen for an astronaut

            Business objective considerations: 

            • If the user is an astronaut, who is the customer? Governmental agencies (e.g. NASA), private companies (e.g. SpaceX), or an alternative?

            Possible user problems:

            • Lack of ink flow in low gravity
            • Extreme space and weight limitations
            • Difficulty writing at any angle, on a range of surfaces
            • Utensils that break easily or run out of ink are difficult to replace quickly in space

            Possible solutions:

            • Pressurized ink cartridges
            • Sturdy metal material that withstands temperature extremes
            • Long-lasting ink or cartridges that are easy to refill

            2. Design an umbrella for kids

            Business objective considerations: 

            • If the user is a child, who is the customer? Parents? Schools or summer camps?

            Possible user problems:

            • Difficulty holding an umbrella due to its weight and size of handle
            • Buttons and opening mechanisms pinch fingers
            • Difficulty opening and closing an umbrella with small hands
            • Easily confused with other umbrellas grouped together at school, on field trips, etc.

            Possible solutions:

            • Smaller, ergonomic handle for small hands, which sizes up by age
            • Easy push-button for opening and closing
            • Customizable design and option to print child’s name in visible spot

            3. Design a phone for deaf people

            Business objective considerations: 

            • Are we targeting partially deaf users, fully deaf users, or both? Mobile phones or a different kind of phone? Adult users or all ages?

            Possible user problems:

            • Difficulty hearing ringtones and text alerts
            • Low resolution or spotty network makes video calling difficult
            • Holding the phone with one hand makes it difficult to sign

            Possible solutions:

            • Flashing LED lights and a powerful vibration to signal calls and texts
            • High-resolution front-facing camera
            • Hands-free case and accessories

            4. Design a car for blind people

            Business objective considerations: 

            • Is it a fully self-driving car, or something like a taxi service for the blind? Will seeing users (e.g. friends and family) also be driving the car? Are there any legal requirements around blind drivers?

            Possible user problems:

            • Driver cannot use any visual-based interface for the self-driving system
            • Driver will not be able to visually track speed and lane changes
            • Seeing users will not need or know how to operate the voice system

            Possible solutions:

            • Voice-controlled self-driving interface that gives audio cues for speed and lane changes
            • Emergency features that self-call 911 and report location in grave cases
            • Auto-parking capabilities

            5. Design a dictionary lookup for scrabble

            Business objective considerations: 

            • Is this for online Scrabble games or the physical board game? Will the dictionary be in print or a website/app? What will set this apart from a standard dictionary? Will it be English-only or need functionality in several languages?

            Possible user problems:

            • Standard dictionaries lack the point score of Scrabble letters
            • Physical standard dictionaries take time to find the right words
            • If a word is not playable, users lack suggestions to other words with the same letters

            Possible solutions:

            • App-based dictionary where users can type in the word
            • Automatic calculation of word value, with options to input triple or double letter-score
            • Options to suggest high-value words with a given string of letters

            6. Design an app for a community of Celiac's disease patients

            Business objective considerations: 

            • Are we designing for a web client or mobile client? Will the community include loved-ones or doctors of Celiac’s patients? Is the principal symptom of Celiac’s disease an intolerance to gluten?

            Possible user problems:

            • Celiac’s patients suffer unpleasant symptoms with confusing and sometimes conflicting information online
            • It is difficult to know what is safe to eat
            • Celiac’s patients don’t always know other patients who share the same symptoms

            Possible solutions:

            • Include doctors on the app who can reply to chat requests and general questions
            • Barcode scanner to report gluten content in packaged food
            • Community forums for Celiac’s patients to share recipes, experiences, struggles, etc.

            7. Design a grocery app

            Business objective considerations: 

            • Is the grocery app affiliated with a specific store? Does it provide recommendations or help buy and deliver the groceries? Is the grocery app designed for the stores or for the customers? Urban or rural users?

            Possible user problems:

            • Consumers often don’t have the time to shop for groceries
            • Difficult to remember what to buy and find the right item among the aisles
            • Difficult to transfer large amount of groceries from store to home

            Possible solutions:

            • Price comparison tool between different stores
            • Grocery list autofill or suggestions for related products
            • Delivery option

            8. Design a washer and dryer

            Business objective considerations: 

            • Is it for commercial or home use? Is the business goal user experience, energy efficiency, price leadership, or an alternative?

            Possible user problems:

            • Clothes wrinkle quickly if left in the dryer
            • Washers and dryers use up a lot of water and energy
            • It is unclear which settings are best suited for different types of clothing

            Possible solutions:

            • Intermittent tumble setting to keep clothes unwrinkled in dryer
            • Detergent dispenser that automatically releases an appropriate amount for the amount of water
            • LED display that suggests settings according to what is being washed

            9. Design an alarm clock

            Business objective considerations: 

            • Is it for a specific age group? Is it only to help people wake up, or also to set reminders or timers? Is this a physical or digital product?

            Possible user problems:

            • Easy to sleep through or fall back asleep after alarms
            • Users frequently forget to set the alarm until they are already lying in bed
            • Sound disturbs others sleeping in the same room

            Possible solutions:

            • Voice control to set alarm from bed
            • Puzzle or physical movement required to shut off alarm
            • Bluetooth connection to headphones or vibrating bracelet to wake up individual users

            10. Design a bike-based delivery service

            Business objective considerations: 

            • Is the service partnered with a specific bike manufacturer? Will it only use standard bikes, or include scooters, electric bikes, or motorcycles? Does the delivery service focus on one area (e.g. groceries, food, etc)?

            Possible user problems:

            • Difficult transporting large objects via bike
            • Delivery bikers slowed down by heavy loads, uphill rides, etc
            • Lack of bike lanes in certain areas

            Possible solutions:

            • Partnership with a popular bike manufacturer to use and sell electric bikes
            • Refrigerated messenger bags and backpacks to transport deliveries
            • Possibility to pay extra for a quicker moped or scooter delivery

            Now that you have a list of sample questions to work with, it’s important to consider how you will practice with these questions.

            4. How to practice product design questions

            It’s best to take a systematic approach to make the most of your practice time, and we recommend the following three steps:

            4.1 Study the company you're applying to

            Get acquainted with the company you’ve applied to. In many cases, the product questions you’ll be presented with will be based on real-life cases the company is facing. If you’re applying to a specific team, study up on their products, the user, etc.

            Take the time to find out which products you’ll most likely be working with, based on the job description, and research them. Look up relevant press releases, product descriptions, product reviews, and other resources in order to discuss what’s most important to the role: the company’s product.

            If you'd like to learn more about a specific company's PM interviews, then we'd encourage you to check out our guide for that company below :

            4.2 Learn a consistent method for answering product design questions

            In this article, we’ve outlined a step-by-step method you can use to solve product design questions. We’d encourage you to first memorize the basic steps, and then try solving a couple of the sample questions on paper.

            This will help you to understand the structure of a good answer. This is a good first step, BUT just knowing the method is not enough, you also need to be able to apply the steps in interview conditions. 

            4.3 Practice by yourself or with peers

            A great way to practice the method for solving product design questions, is to interview yourself out loud. This may sound strange, but it’s an excellent way to improve the way you communicate your answers during an interview. Play the role of both the candidate and the interviewer, asking questions and answering them, just like two people would in an interview.

            If you have friends or peers who can do mock interviews with you, that's a great option too. This can be especially helpful if your friend has experience with PM interviews, or is at least familiar with the process. You can also find peers to practice with on our new PM mock interview platform.

            In addition to practicing by yourself, and with peers, it can be a huge advantage to do mock interviews with experienced PM interviewers. 

            4.4 Practice with experienced PM interviewers

            If you know a Product Manager who can help you, that's fantastic! But for most of us, it's tough to find the right connections to make this happen. And it might also be difficult to practice multiple hours with that person unless you know them really well.

            Here's the good news. We've already made the connections for you. We’ve created a coaching service where you can practice 1-on-1 with ex-interviewers from Google, Amazon, and other leading tech companies. Learn more and start scheduling sessions today.

            cta_illustration arrow_left Browse PM ex-interviewers

            Any questions about PM interviews?

            If you have any questions about product management interviews, do not hesitate to ask them below and we will be more than happy to answer them. All questions are good questions, so go ahead!

            Keep reading: product manager interview articles