Lesson 2: Explaining why

When I ask candidates to explain why during an interview, it’s not just a formality—it’s a core part of how product managers think and communicate. Product managers don’t just make decisions; they need to justify those decisions clearly to stakeholders, team members, and customers. Being able to articulate why you chose a particular solution, why you prioritized one feature over another, or why you think a metric matters demonstrates structured thinking, product intuition, and the ability to influence others. Let me break down why this matters so much, and more importantly, how you should approach it during an interview.

Why Explaining Why

1. It Shows You Have Thought Through the Problem

When you explain why you made a choice, you’re showing that you didn’t just land on a decision arbitrarily. It proves you’ve considered multiple perspectives, weighed the tradeoffs, and can defend your reasoning. Without this, your decisions can seem shallow, and it’s harder for interviewers to see how well you’ve thought through the problem.

2. It Proves You Understand the Impact

Whether you’re discussing feature prioritization, product metrics, or user segmentation, it’s critical to show that you understand how your decisions impact the product and its users. Explaining why proves that you’ve connected your actions to broader business goals or user needs. It’s not just about what you’re doing; it’s about why it makes sense for the product and company.

3. It Demonstrates Communication Skills

Product managers have to be great communicators. In many cases, you’ll need to persuade others—engineers, designers, marketers, and leadership—of your rationale. By explaining why in an interview, you demonstrate your ability to communicate decisions clearly, which is essential for cross-functional leadership.

Where to include a why

The simple answer is: “anywhere you make a claim”. In a case interview you have little else that you can do besides making assertions, and they only have power when you back them up with a rationale. Here are some common points in the interview where I expect you to explain why:

Top-Level Structure: Why is this the right way to proceed with the case?

From the very beginning of your answer, I’ll ask you to explain why your framework looks the way it does. Why are you organizing the problem like this? Why did you choose certain areas to focus on? This helps me see how you prioritize information and structure your thinking.

First I’m going to talk about the goal, then talk about customers, pain points and solutions.

I hear this a lot. Tell me why! Why are these the right things to discuss??

Case-Wide Goal: Why do you think this is the right goal?

When you define a goal for the case (e.g., increasing engagement, improving revenue), I’ll ask you to explain why this is the right goal to focus on. This demonstrates your ability to align your approach with the broader business objectives and user needs.

“I believe improving user engagement is the right goal because our product can’t be successful without our customers using the product.

This argument could apply to any product, but that’s okay. A generic argument beats no argument.

Section Topic: Why is this section necessary?

As you move into specific areas of your case (like customer segmentation, feature prioritization, or metric analysis), I’ll ask you why a section matters. Why did you choose to discuss customer segments before product features? Why is this part of the case important right now?

“I’m starting with customer segmentation because identifying the right target audience is critical for defining the product’s value proposition. Without knowing who we’re designing for, it’s difficult to identify features effectively.”

Section Item: Why is this specific choice the right one?

Even within a given section, every choice you make needs to have a clear rationale. For example, if you choose a specific customer segment or feature, I’ll want to know why that segment or feature matters. This shows that you’re not just making decisions arbitrarily, but based on data or a clear understanding of the problem.

“I’m focusing on this customer segment because they have a lot of reasons to care about this, and they are part of a large and growing population that’s likely to adopt new tech products.”

Why I Do This

1. It Reflects Real-World Product Management

As a product manager, you constantly have to justify your decisions—to your team, leadership, and other stakeholders. Being able to explain why you’re making a choice is critical because you’ll need to persuade others, back up your reasoning with data, and anticipate challenges or trade-offs.

2. It Demonstrates Depth of Understanding

Asking why forces you to show that you’ve truly thought through the issue. It’s easy to throw out ideas, but it’s much harder to explain why one idea is better than another. This depth of understanding is what separates good product managers from great ones.

3. It Makes Your Answer Stronger

Explaining why strengthens your argument by making it clearer and more logical. It turns a simple assertion into a well-reasoned case. And in interviews, the clearer and more structured your thought process, the more confident your interviewer will be in your ability to manage complex decisions.

All that said, don’t just take my word for it—prove it to yourself. The next time you’re preparing for an interview, try this approach. When you build your framework, set a goal, or choose a feature to prioritize, ask yourself why you’re doing it. Then make it part of your answer. I think you’ll find that it sharpens your answer and your reasoning as well.