How you would design a new website, mobile app or application? How would you design a new car, toy, or camera? You may meet these kinds of questions in your works or interviews. It’s not possible to assess every aspect of product design process during a short time session. Therefore, it becomes very important that how you think about user problems at scale, and turn that into a concrete product(s) in a short time session.


As you see, all the questions are either about improving upon an existing product or thinking about a new one from scratch. The more you think about users, the better you can define the problem and solve for those who need it the most. It might be helpful to start with a framework to get the right structure set to your audiences.

The 3 key elements of product sense:

  • Empathy
    • This is how the user is likely to react
    • Keys
      • Cognitive Biases
      • Behavioral Economics
      • Psychology Literature
  • Domain Knowledge
    • This approach gives us an advantage over them
    • Keys
      • Customers
      • Competition
      • Technology
      • Books
      • Online resources
      • Podcasts
  • Creativity
    • Here’s a novel solution to this hard usability problem

The key traits you should be aware:

  • Articulate an ambiguous problem well
    • Who you are building for, why, and how it fits into the mission?
  • Be able to break down the problem into iterative and manageable steps
  • Be able to solve core challenges for the users and being thoughtful about it
  • Be able to reason your way through all your choices along the way
  • Be able to understand whether reasons good enough for company to give a go/no-go
    • Zoom out from your personal user needs and think about how this product could scale and provide maximum value
  • Understand that everything is trade-offs
  • Be good at well-rounded communication skills and deep sense of customer empathy
  • Be concise and do not ramble
  • Good at visualization like drawing wireframes

For clarifying questions we can use “5 W’s and H” way:

  • What is it?
  • Who is it for?
  • Why do they need it?
  • When is it available?
  • Where is it available?
  • How does it work?

But sometimes we just use simplified version which is called “3 W’s and H”, that is, excluding WHEN and WHERE.

CIRCLE Framework

One of the famous ones is Lewis Lin’s CIRCLES ™ framework that lets you provide a well-rounded and thoughtful answer. And it’s a checklist or guideline on what makes a complete, thoughtful response to any product design process.

  • Comprehend situation (Clarify by asking clarifying questions)
    • What?
      • What’s the timeline?
      • What’s the target OS?
      • What’s the goal/mission?
      • What’s the geography?
    • Who?
    • Why?
      • Build communities and bringing the world closer together
    • How?
  • Identify users (Define the users and segment users)
    • Personas
    • User Segments
      • Groups
        • Company
        • School
      • Individuals
        • Staff
        • Student
    • MECE principle for segmentation
      • Stands for
        • Mutually
        • Exclusive
        • Collectively
        • Exhaustive
      • Grouping customers by
        • Defined age brackets where there is no category overlap
        • Country of Birth, assuming no geographical overlap
        • Highest level of education obtained
        • Defined revenue brackets
        • Number of employee brackets
  • Report user needs (Go over user motivations, user journey, come up pain points)
    • As a…, I want…, so that I can…
  • Cut, through prioritization (Come up with user pain points)
    • ROI (Return on Investment) estimate?
    • LOE (Level of Effort) estimate?
  • List potential solutions (Brainstorm)
  • Evaluate trade-offs (Call out any trade-offs, as Nash equilibrium)
    • Thoughtful?
    • Analytical?
    • Objective?
    • Risks?
  • Summarize recommendation (Choose one according to priority, and paint vision)
    • What?
    • Recap
      • Talk about the success metrics (how you’d measure success? guardrail metrics)
        • Customer churn rate
        • NPS (Net Promoter Score) score
          • It’s used to gauge customer loyalty, satisfaction, and enthusiasm
        • Number of product returns
        • Number of customer complaints
        • Number of product defects
      • Have a go to market or a rollout plan
      • Mockup and wireframe user experience
    • Why? vs Others

BUS Framework

It’s a three-step pyramid-like approach to tackle almost every product design problem:

  • Business problem/objective
    • What is the actual root business problem/objective?
      • Company KPI is being affected
      • Revenue
        • Units sold
        • Price per unit
      • Costs
        • Fixed cost
        • Variable cost
      • User Engagement
      • Impact
      • Monetization
      • Partnering with others
    • How do we know that’s a problem?
      • Low conversion
      • Lots of support calls
      • Poor adoption
      • Poor retention
  • User problems
    • Which user problem is causing the business problem?
      • Approaches
        • User interviews
        • Ethnographic studies
        • Diary studies
        • Quantitative metrics
      • Do drill down to really understand user problems
        • “Your site is bad” -> “ clicked a button on my mobile device and the next screen was blank”
      • Present with a good set of data you’ve got (People Understand)
        • Personas
        • User Journeys
        • Flows
    • Why is it a problem? How do we know it’s a problem?
  • Solutions
    • Which idea will solve the user problem, thereby solving the business problem?
      • User tests
        • Split testing
        • A/B testing
          • Control
          • Experiment
        • Multivariate testing
      • Interviews
      • Beta tests
      • Paper prototypes
    • How confident am I that the solution will work?
    • The metrics to know the solution is successful
      • Adoption
      • Retention
      • Monetization
    • Watch out for things (As you are not your product)
      • Confirmation bias
      • Plain old ego

With BUS framework, you need to tackle problem in that order. If you don’t get the business problem right, your run a much higher risk that your final product won’t be successful. But if your business problem is right, the only risks you’re taking are with the user problem and solution. The same applies to the user problem.

Product Problems

The 4 most common prompts for a product sense problems:

  • What is your favorite product and how will you improve it
  • Build product X for user Y
  • Company X wants to solve problem Y
  • Improve product X

Product Design

You need to combine a strong eye for design and UX with an understanding of business problems.


  • Design a social travel product for Facebook
  • Design a jobs product for Facebook
  • Design a product to help users find a doctor on Facebook
  • Design a better way to find roommates in a new city
  • Design an alarm clock for the blind

Product Improvement

The same thing as product design, but instead to improve and existing product.


  • How would you improve Facebook?
  • Pick a Facebook app / any product — how would you improve it?
  • How would you improve Facebook groups?
  • How would you improve Facebook birthdays?
  • What would you build to differentiate Instagram Reels from TikTok?
  • How would you improve the peer-to-peer payments product on either Messenger or WhatsApp?
  • Why was this button put in this place?
  • Why was this animation done in that manner?

Product Strategy

You need to understand competitive markets and to create a product roadmap that responds to the business strategy.


  • Facebook events is struggling. How would you turn it around?
  • Should Facebook enter the dating / jobs market?
  • How would you monetize Facebook marketplace / messenger?
  • What should Facebook do next?
  • How to grow the product by acquiring new users and keep them engaged in the app