System Design Interview for (Technical) PMs: How to Ace It

If you're vying for a technical PM role, you're going to encounter the System Design Interview. And even some PMs will. Here's the concepts, frameworks, and examples you need to ace your next one.

System design interviews are not just for software engineers.

In fact, some of the best companies out there ask them of product managers, program managers, and their technical variants. Here’s what my research is showing these days:

I was recently even talking to an agile coach who was asked one! She was a software engineer 10 years ago, but was worried about an upcoming system design interview.

Interestingly, it’s the type of thing she would’ve aced 10 years ago, but she hadn’t practiced the skill in a while.

Many of you feel the same: you’re terrified of the system design interview.

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System design interviews shouldn’t be scary

System design questions aren’t that hard - from the point of view of concepts. We’re not talking about organic chemistry. If you’ve studied and aced an exam last-minute, you can do the same with system design.

The real reason I think people get so scared is there is no good content for PMs. All the system design interview content that’s out there is for engineers.

Product managers and program managers aren’t held to the same standard as software engineers. So, that content doesn’t really help.

Here’s how I’ve experienced the differences between software engineering and product management system design evaluation criteria:

For instance, at Google, more of the emphasis is on estimation and scoping:

For system design, my interviewer was more interested in estimation and scoping than a technical solution.

—Recent Google L6 TPM Candidate (Got Offer With My Help)

Every company has its own rubric, but the thrust of PM rubrics is: how technically deep can they go? While for engineers, it’s: are they amazing technically?

What little content there is for PMs is either AI-generated drivel or goes to a level of detail that just isn’t fit for non-software engineering roles.

So that’s why I’m writing today’s post.

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The Next in My Interview Series

I’ve covered almost every interview question type relevant to PMs and growth people out there:

• Technical

• Behavioral

• Product Sense

• Product Design

• Product Strategy

• Product Execution

• Product Estimation

Why did this one take a bit longer?

I wanted to make sure to get you market-tested results.

Here is the validated information that has worked to help me help others get PM offers.

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Today’s Deep Dive

These are the proven techniques that have helped me, and PMs I coach, ace system design interviews for technical PMs:

1. What you’ll be asked

2. The framework to follow

3. The technical knowledge you’ll need

4. The common pattern to use

5. Top examples

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1. What You’ll Actually Be Asked

When they say you have a ‘system design’ round, they’re using a broad term that actually incorporates a few different types of questions:

Generally, PMs are most likely to see design a big app. About 50% of the interviews my mentees had asked something like that.

Design a category is the next most common, around 30%. Then you have frontend design (10%) and low-level design (5%) & infrastructure design (5%).

All 5 of those categories are full of follow-up questions from the second layer.

So now that we know what they’ll ask, let’s cover the framework to respond, concepts to understand, common mistakes, and top examples.