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Design a smoke detector for the deaf

Product Design Question for Product Management Interviews

When I was studying for product management interviews with Google, Facebook, DropBox and many other start-ups this was quite a popular question that people got asked.

What is this question about?

This question can also be asked in many other ways like “Design an alarm clock for seniors” or “Design Lyft or Uber for someone that is blind” or “Design YouTube for kids”.

This is a very typical product design question and the interviewer is looking for:

  1. Your ability to think BIG, and creatively
  2. Your customer empathy and ability to identify the right user pain points and needs
  3. Your structured, concise communication

How do you answer this product design question?

Use the cGAPSFramework…

  • Clarify: What are we designing? In this case it is given — a smoke detector. You can ask clarifying questions here, and explain how a smoke detector works. Remember — you shouldn’t jump to solutions right away.
  • Goal: Why are we designing this product?
  • Audience: Who are we designing for? In this case it’s given — your target audience is hearing impaired.
  • Pain Points: What needs are we solving for? What needs might someone with impaired hearing have? What is the biggest pain point out of all of them?
  • Solution: How do we solve the users’ needs? Make sure to narrow down on the best solution, after comparing all of the ones you brainstormed.

Example Answer


  • Ask questions: (1) Is there anything else I should know about this person? No. (2) Are we designing a smoke detector for the persons home only, or one that is used in public spaces too? Let’s focus on their home for now, but you can factor in public spaces if you want.
  • How does a smoke detector currently work? An alarm is an emergency tool designed to save lives. An alarm is usually above the kitchen and hallway, and starts sounding a loud sound when it detects smoke in the house. Alarms can be paused, completely deactivated and some alarms call emergency or the apartment security if left unattended, and smoke is detected.


  • Our goal is to design a smoke detector for someone that is deaf, and make sure this person is protected from potential danger. (goal is already given to us)


  • People that are deaf (audience is already given to us)
  • Going a step further deaf people can have different needs based on: 1) Age: children, teenagers, adults, seniors which all have their own needs, 2) Severity: (1) completely deaf (2) wears hearing aid (3) some hearing impairment, 3) other disabilities: deaf people can be vision impaired, or have other physical and mental disabilities.
  • For the sake of simplicity let’s design for someone that is an adult, can have up to the most sever hearing impairment and doesn’t have any other disabilities at this moment.

Pain Points

General observations to consider about people that have hearing impairment:

  • Deaf is a culture and language: It’s important to acknowledge that many deaf people don’t see being deaf as a disability or pain point within their community. People that are deaf have their own culture, and their own sign language. So we need to design a product that doesn’t make being deaf seem like a disability.
  • Need for seamless integration: They have a goal of living a fulfilling and functional life within their community and also successfully integrate into a world that is designed both for those that can hear and the deaf. So we need to design a product that easily integrates into the day to day activities of the deaf individual.
  • Use other senses (eyes and nose): Deaf people rely on other senses to integrate into their environment. For example, they use their eyesight a lot to use movement, shadows, facial expressions, colors to read the environment, as well as their smell.

Needs & Prioritization…

The following needs are prioritized in order of importance:

  1. Know when there is fire in the house
  2. Other non-def people in the house can understand the danger
  3. Turn off alarm easily
  4. Easily be alerted when out of the house
  5. BONUS: connects to other fire alarm systems when out of house


I’ll brainstorm solutions based on the needs mentioned above:

#1 — Strobe light — LED light attachment to regular fire alarm. The alarm would play a sound, but also a strobe light would flash aggressively with red that can be seen from any room in the house.

  • Cons: only notifies if the person is home, doesn’t wake person up if they are sleeping

#2 — Smart light bulbs. If the central smoke detector detects fire, the light bulbs would turn red, and flash in every room.

  • Cons: only notifies if the person is home, doesn’t wake person up if they are sleeping

#3 — Wearable — vibrating necklace or bracelet which carries smart home functionalities. The necklace or bracelet can change color to red illustrating a fire icon, and vibrate if there is a fire or smoke in the home of the deaf person. This wearable can also come with an app on the phone, which sends notifications to the user, in case they are not wearing a device.

  • Cons: easy to lose

#4 — Visual speaker — for those with hearing impairment to place in their home, which has a large screen and also shows red color, with fire icon and even FIRE spelled out, also playing a sound.

  • Cons: hard to notice

#5 — TV Add-on — for Google TV, Roku, Apple TV that turns on the TVs in the house if the central smoke detector detects fire or smoke.

  • Cons: hard to notice, a bit creepy

Prioritize Solutions

  • All of the above solutions let the user know there is a fire in the house but #1 (strobe-light) and #2 (wearable) do the best job notifying the user.
  • To satisfy the need #2, I will assume every single of the solutions above connects to a central alarm detection system in the house, which also plays a sound for anyone that is not deaf.
  • All of the above solutions satisfy the need to turn off the alarm because all of my ideas are connected to a central system, and the user can just press a button on that system to turn it off. However #2 (Wearable) allows the user to turn off alarm, or act on calling emergency services even if they are not home.
  • Only #2 (wearable) can easily notify the person of the emergency out of the house
  • If we want the user to be notified of a fire in public spaces, the wearable will be the only way to do that, if the wearable partners with central alarm systems in the city. As a downside of course it will be difficult to implement this through partnerships.

Final Recommendation

#2 the wearable solution satisfies all of our 5 criteria. However, as downsides the user might not have it on when sleeping or showering, and also might lose this. For this pretty big downfall I suggest coupling solution #1 which is the strobe Light with a central alarm system that is installed in the house and #2 wearable that connect to this system together. It would be even better if this wearable partnered with Google Home or other Smart Home providers and their alarm solutions.

Like what you’ve read?

I’m Angelina Fomina, and I’m a Product Manager at Facebook, Oculus VR, and ex-Shopify. I also built a 7 figure start-up, and thriving non-profit. I didn’t learn to speak english till I was 12, and I didn’t study a technical degree in University. I also didn’t even know Product Management was a career path until way into my 20s. Now, I’m here to help you build a career you love and tell you that you can thrive in Product Management too!

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If you have any questions — any at all I’d LOVE it if you joined Product Circles. It’s a private Facebook group for you to ask anything you’ve ever wondered about product management. You can also just reach out to me as well —! I’m happy to help.



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Angelina Fomina

Angelina Fomina

I’ll help you do the work you love! Product Manager — Facebook, Oculus VR, Shopify.👇Free product management course