What is good design?

A Product Design Question for Product Management Interviews

The Question

What is good design? Pick a product that you think is well designed and explain why?

Answer Structure

As a PM you will be working with designers to implement product designs that win customers. You need to have a sense of what attributes differentiate a good design from a bad one. The interviewer will be testing you on whether you can articulate basic principles of good design, and whether you can evaluate product designs based on those principles.

One approach to answering this question is to:

  • Explain what your criteria of good design is. You should provide three or more attributes.
  • Pick two competitive products, one which you think exhibits a better design than the other one.
  • Explain what problem the products solve.
  • Then compare their designs using the criteria you mentioned. Pick some common tasks/features and contrast them.

Answer Example

INTERVIEWEE: Design is a very broad term, one could talk about industrial design, interaction design, and experience design. Industrial design focuses on form and appearance; interaction design on understandability and usability; and experience design on emotional impact. Since most of the products your company is concerned with are digital products, would I be correct in assuming that this question pertains more to interaction and experience design?

INTERVIEWER: That is correct.

INTERVIEWEE: Okay. So, I would like to start with describing what I consider attributes of a good design. Then, I would like to contrast two competitive products on their design choices and explain why one is better than the other using my criteria of good design principles.

INTERVIEWER: Sounds reasonable. Please, go ahead.

INTERVIEWEE: A good design has the following characteristics:

  • Understandable — a good design must make it clear how to use the product, what all the controls and settings mean.
  • Easy to use — a good design should be easy to use.
  • Useful — a good design should help the user accomplish the tasks that the product promises to do.
  • Delightful — a good design must provide a delightful experience, so that the user reuses the product.
  • User feedback — a good design provides feedback to the user when errors occur or confirms actions so the user is not left confused.

Now, I would like to talk about the design of the Netflix website and Amazon Prime Video website using some of these principles.

INTERVIEWER: Please, continue.

INTERVIEWEE: The design of the Netflix website is better than the Amazon Prime Video website, and here’s why.

Let’s start with first understanding what the basic use cases these two products are trying to support are:

  1. The user wants to find a movie or TV show to watch.
  2. The user would like to know what she was recently viewing, in case she wants to continue watching later.
  3. The user wants to see ratings of movies and TV shows.
  4. The user wants to read an excerpt of the video to see if it is interesting.
  5. The user wants to watch a trailer before committing.

Of these five basic use cases, 1 and 2 are use cases in which the differences in design choices are most noticeable between these competitors, so I am going to focus on these two cases.

INTERVIEWER: Sounds good.

Amazon mixes “Prime Video” and the “shop everything experience”

Amazon Prime Video website navigation
Amazon Prime Video website navigation

INTERVIEWEE: When I go to the Prime Video site as a Prime Video subscriber, my expectation is to find movies that my subscription entitles me to watch. Instead you find yourself on a page with three navigation menus. The first most prominent menu is for searching and finding things across the entire Amazon shop, the second less prominent menu is for finding movies to watch, and the third menu provides additional ways to search for videos. Because Amazon wants the user to purchase anything at any time, it displays a navigation menu to buy products that have nothing to do with selecting a Prime video, which is the original intention of the user. This can mislead the user to do things he didn’t intend and lead to frustration.

For example, the primary navigation menu which is associated with the entire Amazon shop, has a Departments dropdown list and a Browsing History link. The Departments link takes the user to other Amazon product sites and the Browsing History displays all of the products from the entire Amazon shop the user has browsed in the past. Below the primary navigation menu, is the secondary navigation menu which is associated only with browsing videos. It has links to types of videos, such as Amazon Video, Originals, TV Shows, Movies, and Shorts. Presenting these two navigation menus together, on a page that the user thinks is solely related to Prime Videos can lead the user to doing things they did not intend to do. For example, the user could easily think that the Browsing History link is for reviewing movies she has watched in the past, when in fact it shows all the products she has ever looked at in the entire Amazon shop.

In addition, after the user clicks on the Browsing History link she is taken to another page, and the only way to return to Amazon Prime Video is by using the browser back link or by clicking on Departments > Amazon Video > Included with Prime. The page should provide a direct way back, because the user got there in a direct way.

So, the problem here is that Amazon is using a set of navigation menus for different contexts on the same page, which can lead to confusion.

In contrast, the Netflix website displays a navigation menu that only relates to their video business. So there is no chance of confusing the user.

Netflix website navigation
Netflix website navigation

Amazon displays non-Prime video on Amazon Prime Video

Amazon has three revenue models for its video business: pay-to-rent, pay-to-buy, and free video streaming as part of the Prime program. Therefore, if the user is a Prime subscriber, the user is eligible to watch videos under that program. Yet, when the user goes to the Amazon Prime Video site, what she encounters is a page that shows every video type: pay-to-buy, pay-to-rent and Prime Video movies. The videos that are part of the Prime program are labeled “Prime” and are scattered amongst the many other types of videos. So the user has to scroll and skip rows of thumbnails to find the “Prime” labeled videos or filter them out by selecting a “Included with Prime” link. Needless to say, the experience is exhausting and time consuming. Because Amazon is using one single page to show all videos, Prime and not-Prime, it makes the experience of choosing a movie difficult and overwhelming, not delightful.

In contrast, Netflix completely separates the display of available videos for the different offerings: online streaming and DVDs. This makes the experience of selecting a movie easy.


Both Amazon and Netflix provide the option to browse videos by category or search for videos. Amazon displays categories by rows. Each category row begins by displaying four thumbnail suggestions at a time, and to scroll through more suggestions, the user needs to click on an arrow button at the end of the row. The arrow button allows you to scroll through a total of 20 suggestions for that category. If you want to see more than the 20 suggestions for that category, you have to click on a “See More” link which takes you to a completely different page. To discover all 31 categories requires scrolling down the page about six times. The website does not allow the user to view all of the categories at once. This interface requires too much scrolling and clicking, is not efficient, and does not create a delightful experience for the user.

In contrast, Netflix only has three links to discover videos: Browse, DVD, and Search. The Browse link lists all 21 categories for streaming videos and the DVD link is to rent videos. The navigation is uncluttered and its function is clear. When a user selects a category they are taken to a page that displays the movie thumbnails in a vertical scrolling list, so all movie suggestions for that category are displayed at once. This interface is more efficient and more useful for presenting video information.

So to wrap up, there are four main criteria that I think good designs should have: be understandable, easy to use, useful and delightful. I described how the Amazon Prime Video and the Netflix website designs differ. While Amazon makes the experience of finding and selecting movies confusing, Netflix streamlines this process. The main reason I think Amazon Prime Video does not have a good design is because Amazon wants the user to be one click away from buying other products at all times. And thus, they end up adding interfaces for multiple products, when the user is expecting to be working with one single product.