Edge Cases Are Real and They’re Hurting Your Users

Designing for the “happy path” best-case scenario leaves our most vulnerable users on the margins

Jesse Weaver
Published in
10 min readSep 4, 2019


Photo: Daniel Grizelj/Getty Images

InIn our drive for speed, we have conditioned ourselves to ignore our most vulnerable users. We design for the happy path, and society pays the price.

The happy path

To create digital products, designers often start by developing a set of scenarios or use cases. These scenarios help determine the features, interactions, and technological infrastructure required in a product.

As an example, let’s think about Facebook. When Mark Zuckerberg was initially creating the social network he may have had a scenario like this in his head:

“An undergrad who wants to share pictures from a party with her friends.”

This is a straightforward statement, but even something as simple as this can help a designer conceptualize the kind of solution required. In the case of a digital product, they can start to imagine the screens that might be needed, the elements on those screens, and so on.

Scenarios come in two basic flavors: happy path and edge cases.

The happy path is a scenario where everything is perfectly aligned for the feature/product to work exactly as the designer intended:

“A benign undergrad goes to a party and takes some inoffensive pictures. She comes home to her computer [remember this is early Facebook] with excellent internet connection, she logs in and uploads her photos with no issues, they go into the database and are disseminated to her friends.”

This is a happy path as we think of it today. As Goldilocks might say, everything is just right.

Many designers start with the happy path because it’s the path of least resistance. It takes the least amount of effort to conceptualize because it removes many of the inconvenient complexities that might exist. That doesn’t necessarily mean it’s easy to design; it’s just comparatively simplified.

The second type of scenario is the edge case. Edge cases deviate from the happy path and, theoretically, they happen less frequently than the happy path. There…