Designing for users who didn't yet trust digital banking

A loyalty program starting to fade

In 2020, Interbank was Peru's third largest bank, with over two million customers and the number one credit card market share in the country. 36% of Visa Premia cardholders held what was, for most of them, their very first credit card. In Peru, credit cards carry real social weight, and their benefit programs are a genuine selling point. But Visa Premia's program was quietly fading, and customers weren't feeling the value. Our challenge was to understand why, and design something that could change that, for an audience that was just starting to trust online banking.

Customers were still skeptical

Our research involved three rounds of in-depth interviews with 24 users between 23 and 40 years old, a mix of online and offline clients, all credit card holders. What we found was a group of people who were warming up to digital banking but still carried a lot of doubt. There was a distrust of big institutions, a wariness about hidden fees and banking language that felt deliberately hard to understand. Breaking through that barrier wasn't a nice-to-have, it was the central challenge of the whole project.

Not a lot of benefit

Users felt treated differently whenever they brought their coupons to a restaurant, which was degrading and made for a bad experience overall. Using the program also took planning and effort, since many had to print their coupons at the office, and technical issues or last-minute restrictions often left them paying full price, when all they wanted was to use their coupons in the places they liked.

• “I noticed when I utilised my credit card coupons, they would serve me the smallest piece of chicken.”

• “My coupons would end up expiring since I forgot to print them or bring them to the restaurant.”

• “Restaurants would have a technical issue or come up with a restriction on the spot so I had to pay full price.”

Fully digital, flexible and immediate

After synthesizing the research we built three design principles that would guide everything that followed. The experience needed to be fully digital, removing the reliance on printed coupons and offline redemption. It needed to be flexible, adapting to how people actually spent rather than forcing them into predetermined categories. And the rewards needed to feel immediate and tangible, because users consistently valued smaller, certain wins over accumulating points toward something distant.

From those principles came a clear direction: a cashback model where users could choose which expense categories to apply their coupons to, giving them genuine control over the benefit.

Testing our way to the right solution

We ran four rounds of concept and usability testing with 36 users, working from low to high fidelity across five design iterations. Early on, testing a range of concepts quickly showed us that customizable cashback was the most desirable direction. But testing also taught us something less obvious: the visual language of the product mattered just as much as the concept itself.

Our users were at varying levels of digital maturity, and the redemption process needed to feel familiar enough not to generate cognitive dissonance. If the learning curve was too steep, people would give up before getting any value from it. That insight pushed us toward a more figurative, illustrative visual approach over a purely abstract one, matching how our users thought rather than how designers prefer to think.

A setback that collaboration prevented from becoming a failure

Late in the project, a significant technical constraint surfaced: the tech department couldn't filter expenses by category, something that hadn't come up during their feasibility analysis. Without filtering, users would be left scrolling through unmatched expenses trying to guess which ones qualified for their coupon. It would have handed our technical problem directly to the user.

This could have derailed the project entirely. But throughout the process I had made a deliberate decision to bring developers into the design process early, inviting them to interview sessions, workshops, and synthesis moments. They had built context and empathy around what the product needed to do for users. When this constraint emerged, that shared understanding made it possible to push for the right fix instead of a workaround. Stakeholders agreed that filtering expenses by category was crucial for the program to deliver on its promise and feel valuable to our users, even if it meant dedicating an additional sprint to redefine some of the technical requirements.

Our developers built the filter logic, and users only saw the expenses that matched their coupon, which was a direct result of bringing stakeholders along for the entire design journey.

The new program delivered

Six months after launch, redeemed coupons per customer per month had doubled. Visa Premia holders who became primary app users increased by 10%. Monthly spending per customer grew by €50 on average. Users who engaged with the cashback program also started exploring other features they'd previously only used in branches or at ATMs, paying bills, checking balances, gradually building a relationship with digital banking.

Some users even started planning ahead, waiting until the end of the month to strategically match coupons to their most relevant expenses. We hadn't designed for that behavior, but it showed up once people felt in control of their own coupons.

What I took from it

This project shaped how I think about the role of a designer. Making the design process more accessible to developers is the reason the project survived the technical setback and allowed us to deliver the best experience to our end users. Gaining that trust was as much a user-facing challenge as an internal one.