Product Design Case Study: Design a Smart Fridge

Case Studies
Mitchell KimMitchell KimLast updated

In this post, we'll review a case study submission from one of our Exponent members, Sholanki Sarkar.

Question: Design a Smart Fridge.

If you want to brush up on the basics of answering Product Design Questions, check out Exponent’s lesson on how to ace the product design interview question.

(Sholanki’s answers are in regular font, interviewer’s responses in bold, and the editor’s notes in italics).

Exponent's Product Design Framework

Here is a framework that we recommend you use for Product Design questions.

  1. Clarify the situation (what, why, where , how)
  2. Users
  3. Pain Points
  4. Ideas
  5. Vision
  6. Feature Priority
  7. Pitfalls

Sholanki’s Answers (with Commentary)

Clarify the situation (what, why, where, how)

  • What do you exactly mean by smart fridge? Are there specific target demographics and problems to solve for? Should I consider any business goal other than designing the product?

    We are a startup that wants to enter a home improvement segment. However, feel free to consider new markets to enter if applicable. There’s no specific business goal other than finding product-market-fit.
  • Understood, the market is very saturated and highly competitive in the household segment by companies such as LG, Whirlpool, etc. So the barriers to entry will be very high and we will need to standout by offering an innovative solution.

    I want to start by segmenting different target customers and their pain points, then analyze the pain points to design the product features. I will then prioritize the brainstormed features at the end. Does that sound good?

    Sounds great.


Potential customer segments for the smart fridge that come to my mind are:

  • Grocery Business
  • Restaurants
  • Households

The household market is very saturated and believe every household has a refrigerator, where upgrading the refrigerator  is infrequent. So I would like to turn my attention to the other two tangent segments.

Editor’s Note:

I love the fact that Sholanki did not restrict herself to the initially provided segment (households) and came up with related and potentially more lucrative market segments while providing reasonable justifications of her decision. This was made possible by her taking the time upfront to ask clarifying questions, get on the same page with the interviewer, and even getting a new piece of information (“feel free to explore other markets to enter”) to work with.

Pain Points

To consider common needs and pain points for the two segments,

Grocery Business

  • Most grocery stores do home delivery these days by using services such as Amazon Prime Now, Instacart, etc. The existence of delivery services calls for the need to efficiently select fresh items from the refrigerator as the orders come in.
  • Grocery businesses care about power saving and any other ways to save costs by efficiently managing the inventory.
  • For large refrigerators typical of big grocery chains, it is very hard for the operators to understand where each item is and where there is space.
  • Inventory management requires human effort.


  • Restaurants share a lot of needs and pain points that grocery businesses have, including saving power and cost, managing inventory, understanding where everything is, and potentially the need to deliver food.
  • The ability to understand freshness is also a major concern and requires human effort.
  • Restaurants make food as it is ordered, especially for high-frequency/high-effort/low-value menu items such as ice cream. We can have an instant cooling feature that is taken care of by liquid nitrogen as a default setting (in the case of ice cream).
  • Restaurants must generate food safety reports to comply with the food industry standard. Hygiene is a manual effort that requires continued care and investment with a big potential risk.

    Editor’s Note:

    I like Sholanki’s creativity and user empathy in enumerating these use cases and pain points, which are all actual problems that grocery and restaurant chains have. This kind of broad, holistic brainstorm gives Sholanki a lot of things to work with.

    Conversely, it would have been ideal if after enumerating all these points, she took an additional step to weigh and prioritize them in order, to arm her with a better strategy to sequence these into a practical, feasible, and easily understood solution.

    As you’ll find in the subsequent sections of her answer, while providing a lot of options is great, having too many of them without clear prioritization confuses the interviewer in understanding which exact problem the interviewee is solving. Having too many things to choose from could be a curse rather than a blessing, as product managers often experience during our actual job deciding what to build out of hundreds of different ideas and requests.


Now that we understand the pain points of our target segments a bit better, to paint a clearer picture of the fridge I’ll design:

  • The fridge will provide automatic inventory management with sensors and barcode scanner inside the fridge.
  • The fridge will work like a vending machine with First In First Out (FIFO) order for optimal grocery delivery service without wasting inventory.  
  • Power mode enabled when relatively lower inventory status and during times there is no input expected (no need to automatically scan and enter data).  
  • Freshness report powered by machine learning technology, enabled by the data gathered through the sensor-scanner.  
  • Instant freezing technique which doesn’t require liquid nitrogen (which often causes injury by thermal burn) to efficiently produce menu items such as ice cream.
  • Ability to dismantle refrigerator segments to optimize for space.


Editor’s Note:

One thing that Sholanki’s answer misses is a vision for the future and how her proposed solution will fit into that vision successfully. As Sholanki mentioned in the beginning, smart home appliance market is a crowded market and it is also an industry full of potential with lots of exciting directions for innovation.

Interviewers look for the candidate’s vision, excitement, and articulation of the future during product design interviews, qualities often described as “product sense.” This is a perfect opportunity for Sholanki to demonstrate her product sense by providing an exciting vision for her smart fridge.

For instance, Sholanki could’ve said:“Smart appliances will be universally adopted in the future not only in households but also in restaurants and grocery chains, as the underlying technology and the industry around them are rapidly progressing as we speak. There are many daily problems that owners deal with running a restaurant or a grocery chain, and my smart fridge will go beyond just providing the functionality of a refrigerator and be an executive assistant to its owner, lifting all the headaches and burdens around running their store. Everything from inventory management and automatic restocking to freshness report and smart suggestions to save power and cost, my smart fridge will free its owner from the nitty gritty work so they can focus on growing the business.”

Feature Priority & Pitfalls

The first four features, 1) auto scanning for inventory management, 2) FIFO system for delivery service, 3) power mode, and 4) ML-powered freshness report are applicable to both segments, and due to larger opportunity sizing, I will tag these as high priority.

The last two features, instant freezing and dismantling segments for space optimization, could be sized as medium priority as more applicable to the restaurant segment only.

Editor’s Note:

This is an exciting smart fridge with a lot of useful features that solve previously mentioned user pain points. However, even after the high-level prioritization Sholanki provides, a question that arises once again is whether and how she will go after all four of these high priority solutions at once. Further steps to provide a simple structure or pillars to prioritize these ideas and how she will sequence them if at all would have been very helpful here.

Furthermore, I believe choosing a fewer ideas from the list would have given Sholanki space and time to dig deeper into them and be more specific about how exactly they will work and be implemented. For instance, how exactly will the auto-scanner and the FIFO inventory management be implemented and work in practice? Will it require additional overhead from grocery store and restaurant owners to successfully operate? (would all items entering the fridge need special barcodes or tags?), how will employees interact with the system? (an application or a dashboard solution may be adequate), and whether there will be mechanical engineering and robotics involved to automatically move things around for optimal inventory management are all questions that remain unanswered from Sholanki’s current vision.

Had Sholanki honed in earlier on the specific pain point she was going after, she might have been better equipped to understand how to prioritize and dig deeper into these features, instead of trying to design something that's a jack of all trades, but a master of none. As mentioned in the previous section, Sholanki could have introduced a product vision for the refrigerator earlier on - what is her core tenet and what is she solving for? Even a brief tag-line for the product might have been helpful here.

Feedback from Exponent’s PM Coach

What Sholanki did well:

  • Sholanki beautifully presented and pivoted into a different segment than what was presented by the interviewer with reasonable supporting evidence and clear communication style. This all came out of her time spent in the beginning clarifying the situation.
  • Sholanki was creative in brainstorming user pain points and solutions that solve these actual user needs that added up to paint a compelling vision for her solution.

What the candidate could improve on:

  • Throughout her answer, one thing that stood out as a point of improvement was more rigorous prioritization of her creative ideas. While presenting a lot of options is great as it demonstrates the interviewer’s intellectual versatility and agility, having too many options can get in the way of providing a clear, easily understood solution, digging deeper into a particular idea, and displaying the interviewee’s ability to prioritize.
  • Spending time on defining and painting a clear product vision could have helped with Sholanki’s prioritization as mentioned in the Vision section. Since vision and excitement for the future are one of the most important qualities that interviewers look for in product design interviews, interviewees should take full advantage of the opportunities to demonstrate these qualities during the interview.
  • Since the problem was vague enough in the beginning and Sholanki is proposing to enter a new market to find product-market-fit, it would have been a great addition for her to define clear success criteria with measurable metrics at the end.

That’s a wrap! Thank you so much for reading.

Once again, if you’d like to practice with more product design questions like this, check out Exponent’s Product Design Course.

Thank you so much Sholanki for your valuable submission!

Learn everything you need to ace your product management interviews.

Exponent is the fastest-growing tech interview prep platform. Get free interview guides, insider tips, and courses.

Create your free account