Lesson: Acing product design questions. In this lesson, you will learn how to ace product design questions. The next popular PM interview questions are, as you might expect, product design questions. Here are three examples of product design questions: What are your four favorite Google products? Pick one and describe how to improve it. How would you build a refrigerator for the blind? Lastly, how do you design an elevator for a skyscraper? Note that if you are interviewing for a particular product team, you'll often get asked about refrigerators and skyscrapers instead of the actual product you're interviewing to work on. This is because interviewers are drawn across the company and seek to assess all candidates across common metrics. Here's how I'd answer the question, How do you design an elevator for a skyscraper? Step 1, cross-examine the interviewer. These questions contain a great deal of ambiguity because requirements in real life are ambiguous. Your role before answering the question is to eliminate that ambiguity. Here are sources of ambiguity from the phrase a skyscraper, ask, is this the concept of any skyscraper or a particular skyscraper? Where in the world is this skyscraper located? Who are the tenants of this skyscraper? Skyscrapers have many elevators. So why are we only designing one? How many floors does the skyscraper have? In which floors, will my elevator stop on? What are the uses of each of the floors? From the phrase an elevator, ask, who uses this elevator? What are the user's goals? Who is buying this elevator? What are the buyers goals? Does the buyer impose constraints such as budget? Who's the elevator operator? Do I have internal constraints such as resources available to my team? What are external restraints such as building codes? Now, let's assume the interviewer tells me the skyscraper is yet to be built in North America. Specific location does not matter. It is 83 stories tall in mixed use with retail, office, and hotel. The top floor is a revolving restaurant, observation deck, and gift shop. The elevator is the skyscraper's single outdoor observational elevator on the side of the building. The commercial property management company is the buyer. They want to charge guests $30 to ride up to the top two floors and back down. Guests want to enjoy the view and experience on the ride up and down. We're bidding to build the elevator and don't have a contract yet. We would like to present one or two impressive ideas. If your plan does not meet technical or legal constraints, I will let you know. Now we have a much clear goal. Let's continue to step 2. Step 2, create persona maps for the buyer and the user. Buyer persona, commercial property management company for example, CBRE. Goal, recruit cost of skyscraper, sub-goal attract many people to ride the elevator for $30. Sub-goal, minimize expenses such as maintenance and opportunity costs, such as downtime. Demographic, a group of people from a general manager to security, to maintenance. Psychographic, wants to attract tenants and charge them top dollar, fear of negative publicity. Success metric, net income. User personas, affluent tourists, affluent couples, think night, work team after hours, business meeting guests. Goal, enjoy the experience. Sub-goal cleanliness. Sub-goal, privacy from those looking in. Demographic, generally 30-60 years old, well-to-do groups of experience seekers. Psychographic, wants a memorable experience, fear of accidents. Success metric, number of tickets purchased, NPS, CSAT, net easy score. Step 3, start listing features to fulfill each of the goals. As a user, goal is to enjoy the experience. We're not designing the fastest elevator in the world, but the most elegant. Equip it with a luxury sound system and soundproof against external sounds. Lush red carpet. Present menu of programs for riders to select from. Program, romantic music. Another program, trivia for work groups. Another program, history of the city you see before you. Another program, educational game for kids, can try augmented reality experience on the class. Indicate points of interest or physics of how elevators work. Sub-goal, cleanliness. Fingerprint proof surfaces, periodic check by attendant to see if it should be cleaning. Sub-goal privacy from those looking in. One way glass. Set the elevator inside the building lobby so no one can tell who's riding the regular elevators and who's riding the external elevator. Buyer. Goal is to recoup the cost of the elevator, recoup cost of the skyscraper. Sub-goal attract many people to ride the elevator for $30. Engage a PR firm to get it featured in local media so people are aware of it and build demand to ride it. For example, if in Philly feature it on It's Always Sunny in Philadelphia. Work with the skyscrapers, restaurant, hotel, and other businesses to offer package deals. Sub-goal, minimize expenses such as maintenance and opportunity cost, such as downtime. Equip the elevator with diagnostics and AI to predict downtime and track routine maintenance. Elevator maker ThyssenKrupp makes these already. Customers should be able to reserve a time and buy tickets online using a website or app without involving building staff. Customers should be able to use a QR code from their phone to enter the building and call the elevator without involving building staff. Customers should be asked for feedback after their trip using a website or an app. Step 4, summarize and name your product like the headline in a PR. In this use case, we have a luxury elevator that is external. Why not the SightGlass experience? How do you get good at product design questions? The general advice is to spend several hours studying 6-9 different products you commonly use throughout your life. If you are targeting specific companies, focus on them and their competitors. Otherwise, capture a good mix of physical and digital products. Analyze them with every tool you learned from this course. I've made a template for you to use, which you can copy and fill out here.
