Finding the right path

We started by analyzing Nubank’s current revenue composition, which was largely concentrated in:
- invoice and purchase installment plans
- personal loans
- credit card transaction fees

Most of these initiatives were already under the responsibility of our squad, increasing our challenge to lead the next wave of growth.

With a long list of ideas, I facilitated a cross-functional workshop, bringing together data scientists, engineers, customer service (SAQ), lawyers, product managers, and credit card leadership. The goal was to collaboratively assess which initiatives were worth prioritizing.

Evaluation criteria we used:

Technical complexity

Would the initiative require collaboration with other teams?

Would our current financial services infrastructure support it?

Risk

Was the initiative within regulatory authorizations?

Would there be any credit exposure or default risk?

Product and user experience

Are users willing to pay interest for this functionality?

Could it promote harmful financial behavior?

Is the product easy to understand?

Revenue potential

What is the estimated financial return?

What are the competitive advantages?

I compiled all the insights into a strategic deck, which served as the basis for leadership decision-making.

The chosen initiative: Pix on Credit

After validation from credit leadership, we kicked off the discovery for Pix on Credit, a bold and unprecedented proposal at the time.

What is Pix on Credit?

Pix, launched by the Central Bank of Brazil in 2020, revolutionized payments in the country: instant, free, and available 24/7. By 2025, it had surpassed credit cards and was used by over 90% of the adult population.

Our proposal was to enable users to make Pix transfers using their credit card limit, with the option to pay in up to 12 installments with interest and IOF tax applied. A solution that combined the convenience of Pix with the flexibility of credit.

User research

Together with UX Researcher Ricardo Perotti, we designed a two-part study:

Qualitative: 10 in-depth interviews with customers of various credit profiles

Quantitative: survey with over 2,400 responses

Study goals:

Do customers understand the concept of using credit with Pix?

Does it make sense to pay for a transfer in installments?

Is the product more suitable for P2P, P2B, or P2G transfers?

What are the best moments to offer Pix on Credit?

Is the transaction flow intuitive and clear?

Is it obvious to users that there is an interest fee?

Where would users expect to find transaction details?

The qualitative interviews revealed real usage scenarios, needs, and concerns. The quantitative survey helped validate hypotheses and segment high-potential user profiles.

Structuring the flow and dealing with regulation

We created detailed user flowcharts to map the journey, align technical requirements, and ensure legal and security feasibility. These flows were constantly reviewed with engineering, compliance, legal, and security teams.

Initially, the suggestion was to make minimal changes to the existing Pix transfer flow to preserve its simplicity. However, we realized that adding a bit of friction could improve transparency, especially regarding fees and credit use.

We encountered a regulatory challenge: some changes might conflict with Central Bank recommendations. With support from the legal team, we presented our proposal directly to BACEN, demonstrating how our approach prioritized user clarity.

The involvement of Public Policy and Compliance teams was crucial to ensure the final experience was transparent, safe, and compliant.

High-fidelity and prototypes

With validated flows, I built high-fidelity prototypes using Nubank's NuDS 2.0 Design System, detailing:

Edge cases

Animations

Visibility rules

Entry point logic

Key design decisions:

1. Payment method selection

The call-to-action was updated to prepare the user for the next step — choosing the payment method. The layout preserved negative space to maintain focus and reduce cognitive load. This also improved the visibility of the Pix on Credit entry point.

2. Choosing between account balance or credit

The user was presented with a clear decision: use account balance or credit limit. Icons supported visual recognition, enhancing scanability. Options were ordered with balance first, as it was the most frequent choice.

We also displayed the monthly cap for credit usage upfront and explained the interest cost clearly. Legal disclaimers appeared conditionally when the credit option was selected to avoid unnecessary information clutter.

3. Installment selection

This screen introduced the installment feature — a major differentiator. We debated whether to always show this screen or default to one-time payment and let users adjust later. We opted to show it during launch and test via A/B experimentation later.

A subtitle clarified that the recipient would receive the full amount instantly — a recurring concern identified in interviews.

The final amount (transfer + interest + IOF) was clearly displayed. The action button was intentionally narrow to signal continuity rather than immediate confirmation — many users used this screen to simulate costs.

4. Final review

This screen was shown only to users selecting the credit option. Those using account balance were directed to the PIN confirmation screen.

We reinforced that the transfer remained instant, confirmed the payment method, and transparently broke down the total cost, including the Annual Effective Cost (CET). The goal was to maximize user understanding before completing the transaction.

Results

Pix on Credit launched in July 2022 as an innovative way for customers to use their credit card limit to make Pix transfers with installment and interest options.

2022 — Initial traction

Although launched in the second half of the year, the product showed early promise. While detailed revenue data wasn't yet available, leadership highlighted that Pix on Credit and similar initiatives like Boleto Financing contributed to the growing interest-bearing credit portfolio — signaling revenue impact potential.

2023 — Exponential growth

In 2023, Pix on Credit became a key revenue driver:

13.6 million customers had used Pix on Credit by Q4 — a +166% increase year-over-year.

This represented over 35% of Nubank’s active credit card user base.

The share of financed transactions rose from 19% to 21%, boosting interest revenue.

Interest-bearing credit portfolio reached US$ 8.2 billion in Q4 2023, a 91% year-over-year increase.

Leadership highlighted the high margins of Pix on Credit as a disproportionate contributor to growth.

Beyond direct interest and fee revenue, the product also boosted user engagement and ARPAC (Average Revenue per Active Customer), reinforcing its strategic value.

Early 2024 — Continued expansion

Q1 2024 results confirmed the upward trend:

The share of the credit card portfolio with installment balances rose from 23% to 26%.

Growth was mainly driven by increased adoption of Pix on Credit and Boleto Financing.

Leadership reiterated that these products had strong demand and profitability, key to engaging high-value customers.