Selected case studyFintech · Pay by Bank

Clarifying the
bank handoff.

How mixed-methods research turned an ambiguous authentication transition into a clearer experience — and a measurable lift in completed payments.

My roleLead UX Researcher
MarketsUS + Europe
ProductPay by Bank
01 / The decision

The product question

A small screen carried a large burden of trust.

Users were leaving a merchant experience and moving into bank authentication. The screen between those moments needed to explain the transition quickly, reduce uncertainty and preserve momentum.

What must people understand before they feel ready to continue?

Research framing Study design Moderation Mixed-methods synthesis Product translation
02 / Research strategy

Method followed the decision

One question.
Three evidence stages.

I separated exploration, validation and behavioral measurement so each stage could answer a different question — without overstating what any single method proved.

Qualitative exploration

Understand the mental model

Fourteen moderated interviews across the United States, United Kingdom, Germany, France and Sweden revealed how people interpreted the handoff — and where meaning broke down.

14interviews
across 5 markets
03 / The insight

The mental-model gap

The problem was not simply “trust.” It was missing context.

People needed the screen to answer four questions before the next step felt legitimate.

  1. 01

    What am I doing?

  2. 02

    Why am I doing it?

  3. 03

    What am I approving?

  4. 04

    Why should I trust this?

04 / Validation

Language as product behavior

“Verify” described the action. “Go to” described the motion.

The validation did not choose copy by taste. It tested whether the words matched the task people believed they were about to perform.

VERIFYNet preference
UK
+35.3pp
US
+19.6pp

Names the security action and gives the handoff a reason.

GO TONet preference
UK
−29.4pp
US
−37.3pp

Signals navigation, but leaves the purpose of the transition unclear.

05 / From evidence to design

Research as a decision system

Findings became requirements — not a list of observations.

Evidence Design requirement Screen direction
The transition lacked a clear purpose. Name the action. Verify with your bank
More explanation could add effort. Reduce content and sharpen hierarchy. One headline, two supporting points
Credential handling was a source of uncertainty. Make privacy reassurance explicit. Credentials remain private
06 / What shipped

The production experiment

Not a copy swap.
A clearer hierarchy.

The variant combined a new headline with less content, a focused explanation of authentication and explicit reassurance about credential privacy.

ControlExisting experience
Control production screen with longer bank connection explanation

Scope of the claim: the A/B test evaluated the complete communication hierarchy. It did not isolate the causal effect of one word.

07 / Outcome

Behavioral result

Research made the handoff easier to complete.

The result was internally confirmed as statistically significant.

Control
42.79%
Research-informed
44.10%
+1.31pp absolute lift 3.06% relative improvement
42,230transactions
9,004control completions
9,343variant completions
08 / AI-enabled research

AI with evidence boundaries

I use AI to make research knowledge cumulative — not to replace research judgment.

01

Verified inputs

Canonical records preserve source, market, sample, quotations and metrics.

02

Grounded assistance

Gemini and Claude workflows support synthesis, documentation and retrieval from approved evidence.

03

Human decisions

I frame the question, challenge the output and keep claims inside what the evidence can support.

Faster retrieval. Stronger traceability. No invented certainty.
09 / Transferability

The pattern travels beyond Pay by Bank.

The same research logic applies wherever people cross a boundary they cannot fully see: wallets, P2P transfers, bank linking and authentication flows.