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  • Writer's pictureSugat

How to Approach a Product Design Question in Interviews

Yesterday I was at ATM when I saw a blind person trying to withdraw cash. There was a huge queue outside the ATM and it took a longer time than usual. I thought of helping the blind person by withdrawing the cash and offering my help. The blind person, initially, was a bit resistant to seeking my help but later I was able to help him. I have been using ATMs for quite some time now and I believe it’s a brilliant product that helps in withdrawing cash. What I didn’t realize was how this product (ATM) is being used by multiple people and in different ways.

(Here is a small video of a blind person using ATM – Link)

It left me with a thought of how being a Product Manager can improve the ATM so that it can be used seamlessly by Blind people as well. It reminded me of my days when I was interviewing at Publicis Sapient and a similar question was asked me in my Product Interview.

How will you build an ATM for blind people”, and “What is your favorite product and how would you improve it” – These are a few of the typical questions asked during any Product Management interviews. Candidates tend to struggle due to a few of the following reasons:

  1. Jumping into the solutions directly.

  2. Don’t ask clarifying questions

  3. Too attached to initial ideas.

  4. Don’t have any idea to approach the question.

The purpose of this article is to help candidates in structuring their thoughts and preparing them for the Product Design Interviews. This will not only help candidates appearing for the Product Interviews but will also help Product Managers to design a new product.

Methodology – There are so many ways to approach a Product design question. Design Thinking is an amazing methodology to solve any problems. What I personally prefer is the “CIRCLES method” by Lewis C. Lin. In his book “Decode and Conquer”, he shared step by step approach to tackling any product design question. It starts with analyzing the situation to recommending the solution.

In this article, I will be sharing details about the “CIRCLES” method, along with taking examples to solve real-life problems.

C – Comprehend the Situation

I – Identify Customer/Persona

R – Report Customer Needs (Use Cases)

C – Cut through prioritization

L – List Solutions

E – Evaluate Tradeoffs

S – Summarize Recommendation

Design an ATM for Blind People

Let’s start applying the CIRCLES method, starting with

C – Comprehend the situation

Always start with a Clarifying question:

  1. Are the people partially blind or completely blind?

  2. Will the ATM be accessible for everyone or only blind people?

  3. Tell me something more about the product? Does it helps in both withdrawing and depositing cash?

The interviewer will definitely help you in answering these clarifying questions, in order to set the assumption right. Else, you are free to make your own assumption.

For the above questions, let’s assume that:

  • The people are completely blind here.

  • ATM will be accessible to everyone.

  • This ATM will be used only for withdrawing cash.

We also have to define the North Star metric.

(A North Star metric is one key metric that defines the success of the product. It focuses on the core value that the product delivers to the customer. For example, for Facebook North Star Metric will be “Daily Active Users”, For WhatsApp, it will be “No. of messages a user sends”)

For ATM it will be the “No. of transactions done by Blind people per day

I – Identify Personas

Although we are designing this product for blind people, there are different persona for blind people as well

  • Senior Citizen

  • Working professional

  • College Students

We have to dig into one persona and discuss the use cases. You may ask the interviewer if there is a particular persona they would like to go ahead with. Or you can go ahead and pick one of them based on some hypothesis.

In this case, let’s go ahead with the persona of

Working Professional - Based on my observations, most of the blind working professionals are alone and they might be frequent visitors to Banks for withdrawing amounts.

R – Report Customer Needs (Use Cases)

This is one of the most important phases, where we have to identify the use case and what the pain points we are trying to solve are. In order to list the use case, one of the ways is to look at the customer journey.

These are the stages for withdrawing an amount from ATM.

There can be many more use cases. Listing around 5-6 use cases can be a good number.

C – Cut through prioritization

All the above 3 stages for ATMs seem to be very important and play a vital role. In the journey of withdrawing cash, you either have to visit a bank or an ATM, (locating and reaching the ATM/Bank might have a similar effort). What’s currently a pain is the withdrawal part. I will go ahead and focus on the last stage i.e. “Withdrawing the Amount” from ATM.

L – List solutions

There are the solutions I can think of that will help blind people in withdrawing cash.

  1. Mobile App – We have been using apps for transferring money, why can we use the mobile app as a debit card as well. The idea of this app is to act as a debit card as well as a place to enter information. The user can enter the details in the mobile app and connect with the ATM just for cash withdrawal.

  2. ATM on the Move – We have always assumed ATMs to be fixed machines. Instead of going to the ATM, why can’t ATM come to us? We can think of changing the entire process of withdrawing money, where the cash can be delivered to our home, just like food. The order can be placed in the Banking application and the cash will be delivered to your doorsteps.

  3. Smart ATM – If the mobile phone can be smart why the ATM can’t be? ATM can have features like facial recognition/fingerprint followed by a voice assistant (like Siri or Alexa) that will help us to interact with the ATM in a seamless manner.

After listing the solution, it’s time to find the most feasible option. We can’t implement everything at the same time and these are altogether different solutions.

The ATM on the move seems to be the most feasible option, it not only solves the Withdrawal process but also tackles the problem of “Locating and Reaching the ATM”.

E - Evaluate Tradeoffs

Let’s look at what are the challenges and edge cases of the “ATM on the move” option.

  • Although it will help to ease the blind person in withdrawing cash, there will be an operational cost that will be involved with the delivery of the cash.

  • There might be chances of a few locations that might be serviceable for delivery.

  • The delivery of the cash can be delayed and might not be instant.

S – Summarize Recommendation

My recommendation for designing an ATM for blind people is to come up with the concept of an “ATM on the move”. This process will change the current ways of withdrawing money. It will not only solve the problem of withdrawing cash but also the pain of locating and reaching an ATM.

Key Takeaways

Typical interview questions don’t have any right or wrong answers. It’s all about your approach to solving a problem. The interviewer is always interested in the approach rather than the solution. Here are a few things you should keep in mind:

  1. Never divide or show the steps like C. I. R. C. L. E. S. during the interview, it’s just a framework to keep you aligned. In this example, I have divided the steps just for clarity.

  2. Take a pause and check with the interviewer if you are on the right path.

  3. Keep the interviewer engaged and share your thoughts.

  4. Try to be as creative as possible.

If you follow the above approach, I am pretty sure, you will ace your next product interview.

Feel free to watch a mock interview on the question. "Design an ATM for Blind People"

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