Each company will have their own approach to building, shipping, maintaining and iterating on product.
As you approach a PM interview, it's helpful to think about what type of product organization you're interviewing with because it will highlight how and why you might be a great asset to the team. There are a myriad of different aspects to any company's product management organization and how it operates but a few key ones stand out:
At the end of the day, every product organization has a north star that tends to guide them. Some product organizations tend to have a collectively technical mindset (e.g., Facebook or Google), some prioritize the user experience first (e.g., Airbnb or Slack) and others default to analytical insights and the business case (e.g., Amazon, Uber).
The key question is where on the spectrum a product organization, as a whole, is. For example, some companies like Zynga, the gaming company, are known to be extremely analytical and quantitative and put relatively little emphasis on design and user experience. A company like Airbnb started on the other end of the spectrum with a significant focus on user experience and design of the products and relatively little emphasis on quantitative analysis.
Facebook is known primarily for having a very technical group of product managers, with many coming from prior engineering roles or as founders of their respective companies. Amazon tends to seek out more business oriented PMs and hires almost exclusively from top MBA programs.
Where a product organization falls on the spectrum isn't an exact science, and obviously as product teams expand, the makeup of those teams is likely to pull change as well. Additionally, product teams that start on one extreme end of the spectrum may adjust as they see benefits to incorporating more aspects from a different approach. Airbnb is one example that started with an extreme design focus and shifted closer toward the middle of the spectrum by increasingly ensuring they're running useful analytics as well.
Another key dimension is the stage of the products. If you're joining an early stage startup, the product and company itself might be in the pre-launch phase. On the other end of the spectrum, if you're looking to join Google's AdWords division you're joining an extremely established product and will be looking to maintain and iterate on it.
The nature of your product management job will depend, in part, on which stage the product is actually in. For example, in a pre-launch product, the amount of user engagement analysis you'd do is zero - because there is no usage to analyze. However, on an established product with millions of users, you might spend a large chunk of your time analyzing existing user behavior looking for ways to improve the product.
Quite simply: how often does the product and/or company ship product?
Some product organizations prefer an extremely quick release cycle and ship product on a weekly or even daily basis (e.g, Quora). Some organizations run much longer product cycles and prefer to ship new updates bi-monthly, monthly, quarterly or even annually (although this is much less common unless it's a hardware product.).
It might seem like an odd aspect to dig into, but the release cadence of a product organization will have a lot of direct impact on how the organization operates. For example, if the team ships daily or weekly, the organization might put more emphasis on shipping quickly, learning and iterating versus extensive pre-launch planning and analysis. If a company releases quarterly, the reverse is likely true - after all, in that case you only have four releases per year so you better get them right!
Another helpful sign post in determining the product philosophy is who the product organization reports into.
For example, a product organization which rolls up to the chief operating officer (COO) is likely to be more sales driven. Conversely, a product organization that rolls up to the company's chief technology officer (CTO) is, all things equal, likely to be much more engineering and technically focused. If the product org rolls directly into the CEO, it might reflect the personal strengths of him/her.
Real interview questions. Sample answers from PM leaders at Google, Amazon and Facebook. Plus study sheets on key concepts.