Use Case vs. User Persona

Sep 8

One of the thing that confuses and frustrates people with product management case interviews, is when and how to segment users. In most design case interviews, the candidate needs to show that they can segment users and then prioritize one.

In open-ended cases, it is helpful to focus on the motivations, mindset or behaviors of users. But when improving a case for 1B+ users, often the Job to be Done (JTBD) framework is best.

Quick Rule of Thumb

User Cases (JTBD) for Products At Scale
User Personas for Greenfield Products

Think:

Improve Spotify
Improve Nexflix
Improve TikTok
Improve Instagram

vs.

You are the CEO for X, what would you build. (i.e. X = education)
Design a teleportation device.
Design an app to find parking

And the list goes on.

Remember, I said it was a rule of thumb. You can see how a JTBD would work for all of the last three cases. But because it is a new product, it might help you to visualize the person and share that with your interviewer.

Practically Speaking

I find with large products, the interviewer is looking to see if you can segment users but ALSO think about products at scale. Yes, when you have a startup, you focus on a the super-specific who. But when you are working at scale, you want to identify a problem that applies to millions or billions of users. That is often easier to do if you think in terms of the job to be done by the users.

In a recent TikTok case I did, you can see I focused on the job to be done. In fact, I could have dived in deeper and made my user cases for search more specific an still addressed concerns applicable to millions or billions of users.

What is the difference?

Now others might use a different set of terms, but the way I see it is a User is a person you can empathize with and imagine, a persona. A use case to me is a job to be done, some specific problem you need to solve. I find using examples is best.

Two Examples

Parent <> Child Issues