Update: I wrote a slightly updated version of this topic and published it on Medium.
Typical Product Manager interviews will consist of questions in the following areas:
Behavioral
Technical
Analytical
Product sense
Strategy/vision (for somewhat senior candidates)
Some companies will explicitly judge your performance in areas like creativity, leadership, and cultural fit, but even then, the types of questions they ask to assess this will fall into one of the above categories. I will share the types of questions in each group and how to prepare for them.
Behavioral
These are questions primarily about your experience, your personality, and how you would react in hypothetical scenarios. Examples of questions include:
Tell me about your current (or past) job.
What's your greatest strength (or weakness)?
What are you most proud of?
Tell me about a difficult situation you had with an engineer and how you resolved it.
What gets you excited (or frustrated)?
What is the first thing you would do if you found out 30% of your user data was deleted by accident?
Why do you want to work here?
Generally speaking, the best way to prepare for these is to have solid answers prepared for most of them. A practical way of doing this is coming up with 5-6 concrete stories from your experience in the past were you learned something important. For example, a confrontation/disagreement you had with someone, something that made you really happy to accomplish, a particularly hard project you worked on, and so on.
You should have a list of all of these stories before you go into an interview. Once you are asked a question, mentally scan through the list to see if any of them constitute a solid answer.
Technical
Technical questions are there to make sure you'll be successful working with engineering teams. Specifically, you have to earn their respect/trust, you have to understand the systems they build, you have to be able to field technical questions about your product when asked by other teams/companies, and more. Examples of technical questions include:
What is the biggest technical challenge you have faced?
How would you build an algorithm that finds the closest gas station in your route to work?
How many TB of data does a company like Twitter need to store?
What happens when you type www.facebook.com on your browser?
How do you determine a caching policy for a mobile email client?
Technical questions are some of the hardest to prepare for, because if you don't have a strong Computer Science background, it's nearly impossible to do well in this area; building a solid CS foundation can easily take years.
I have found that the best way to prepare for these kinds of questions is to actively write code as a hobby. This means writing scripts to automate repetitive tasks, using APIs to get data from existing services, building a small website or mobile app, etc. When you do this, you'll often end up randomly surfing the web, learning from Stack Overflow, landing on some obscure blog that will teach you a new engineering trick, or reading how a specific protocol/technology works on Wikipedia.
For example, I like how Instagram built their trending feature, this take on how to scrape Facebook data for statistical analysis, debugging an iOS app with Charles proxy, and how to sort data with star ratings properly.
Analytical
An important area that gets attention in Product Management interviews is analytical skills - these summarize your ability to think critically, make rational decisions, and your capacity to solve problems, even when they're abstract. Examples of analytical questions:
How does Uber determine when to start surge pricing?
In a hotel with 4 elevators, what's the optimal strategy they should have?
How much money does Google make on advertising per day when people search for "lawyer"?
Say you run an A/B test. Your experiment idea increases time spent in the product, but reduces revenue. Do you ship it?
Say you build a new fitness app - how do you find your first 10,000 users?
How many books get published in the US every year?
The vast majority of analytical questions don't have a "correct" answer. This means the process you use to arrive at your answer is far more important than the solution itself. When that process is methodical, you consider many options, can evaluate the pros/cons of each proposal, define a framework to make decisions, and justify your steps along the way, you generally end up doing well.
A good way to prepare for these is to pick random questions (you can find some in the resources section below) and practice thinking about them. Over time, you'll start noticing patterns for how to break them down, consider all the options, pick a set of criteria to optimize, and learn how to explain your decisions to others.
Product sense
Product questions will test your intuition for knowing what users want, and whether you have the skills necessary to build a product that satisfies those needs. They encompass anything from design, to competitive landscape, how to prioritize features, etc. Some examples of these questions are:
How would you design an advanced washer & dryer?
What is a product you really like? What would you improve?
What is a product that has serious flaws?
Say you want to build a commenting feature. How are comments displayed and sorted? Do you allow nested comments? How do you moderate comments?
How would you implement a product to get app recommendations?
How would you prioritize the upcoming roadmap for Spotify?
The most practical way to prepare for these types of questions is to pick 2-3 products from the company you're applying to, and 2-3 products from other companies. You then try to critically analyze every detail of those products: Why is the main screen/page the way it is? Who are the main competitors? What do you not like about this product? What ideas/features have you seen in other products that could apply to this one? How does one navigate the product to find all the functionality? What is the purpose of each element on one of the screens/pages?
It's also a good idea to prepare 1-2 products that are not well-known. If you're allowed to pick a product to discuss, it's a good idea to go for one of those - the interviewer has less information about it and it's easier for them to assess your approach as novel. Also, for well-known products, the interviewer has probably head the same ideas from dozens of candidates before, so it's hard for you to stand out.
Even if you're not actively interviewing for a PM job, a way to improve your product sense is to constantly evaluate your experience using day-to-day products. What frustrates you? What is clever? What was simpler than you anticipated? Would you have done it in a different way?
Strategy/vision
Strategy questions are more common in senior candidates - folks who have professional experience of 2-3 years or more. While knowing the details on how to build products is very important for a PM, sometimes it's important to take a step back and understand the bigger picture. Examples of strategy questions include:
Why did Facebook buy Whatsapp when they already had FB Messenger?
How many versions of Windows should Microsoft offer?
When should you buy vs build vs partner for a technology your company is missing?
How do you grow Uber usage by 10x?
How can technology help lower US Healthcare costs?
Which companies will be the most successful in virtual reality?
Strategy questions can be daunting, because they're often very open ended. Also, it's really hard to learn about strategy without seeing senior folks in action. The majority of executives at tech companies don't share how they make decisions in public, so it's hard to find good answers to difficult strategy questions out there. Therefore, the best way to prepare for these kinds of questions is to observe how senior folks make and share decisions in your company.
Interview coaching
If you're interested in getting training for your PM interviews with me, I offer 1:1 Product Management coaching.
Recommended resources
thepminterview.com - sample questions with a nice timer interface
Cracking the PM interview - probably the best book on the subject
Decode and Conquer - I haven't personally read it, but have seen it recommended elsewhere and it has good ratings
The Art of Product Management - nice blog on Product Management by Jackie Bavaro
How to hire a Product Manager - a specific post by Ken Norton on what a seasoned interviewer looks for
What I look for in a Product Manager - another take on what interviewers look for
This is Product Management - a podcast dedicated to interviewing PMs