Paidy App

Fin Tech

App Redesign


Paidy is a fast growing fin tech start up which allows their users to shop online using just their mobile phone number and email address. With cashless payments becoming more popular in Japan, the business plans to eventually become a financial eco-system.

In order to support this vision, the current app had to be redesigned in a way that allows for new products and features to be easily integrated. 

With the project being officially kicked off, it also meant that we had the opportunity to improve the current user experience of the much needed app and provide a better value proposition to our users.


The first problem we faced and found was the infrastructure of the back end system and the way our data were stored. We found that making even the slightest improvements to the user interface would require a lot of changes to the back end system.

The second problem we faced was the current app's information architecture was outdated and it didn't handle all the edge cases well. The information displayed were cluttered making it hard for users to understand their usage and finances.

The third and final problem we faced was the current app didn't provide enough value therefore the retention rate for the app suffered greatly. Users were only using the app to pay their bill and occasionally check their usage.

Paidy overview


1. Review the App

The first task we did together as a team was to review the entire app. This included looking at the analytics data, current information architecture, user flows and goals.

We already had a rough idea where improvements needed to be made but to make sure everyone was on the same page we help some workshops to review the app together with the product team. The workshop helped identify where the gaps and problems were.

Paidy App Information Architecture

2. Reviewing the Personas

Before we dived straight into the solution, we wanted to make sure that everyone understood our personas and that they were up to date. Because of the rapid growth of Paidy and the goal for the year, we created and added an extra persona.

Paidy App Persona

3. Redefining The Problem Statement

The next step was to redefine the problem statement of the app. To help everyone write what they thought the problem statement should be and then to be discussed as a group, we used this format User > Needs > Because.

4. How Might We Questions

After defining the problem statement, we each broke the problem statement down into small questions by asking ourselves how might we? This was to help generate ideas for the next step.

5. Customer Journey

The most important step of this process was creating the ideal customer journey to deliver the best possible solution to our customers. There were a lot of edge cases at Paidy and it would have taken a long time to create a journey for every one of these edge cases so we only focused on happy path of what envisioned the experience to be.

Paidy App Persona

6. Low Fidelity Brainstorming

After creating the customer journey together, we brainstormed for hundreds of hours on many different flows and solutions to improve the user experience of the app.  

During our brainstorming sessions, we constantly included people from different departments such as engineers, product managers, customer support and marketing.

Paidy App Low Fidelity Brainstorming

7. Usability Testing

Once the low fidelity prototypes were complete, we decided to create high fidelity mock ups for a usability test to validate our ideas and hypotheses. 

We conducted 5 face to face usability tests which were 1 hour long. The usability tests were task based followed by open ended questions. 

To record the user test we used an Apple Macbook pro with a custom bendable camera and OBS streaming software.

Paidy App Usability Testing

8. High Fidelity Mock Ups

After the usability test, we summarized the findings into a report and made the necessary changes needed for the app.

Paidy App High Fidelity Mock Ups

9. User Flows in Overflow

Once the mock ups were made we used a cloud based tool to create all our user flows and edges that could be use to easily explain to engineers and product managers.

Paidy App User Flows

Other Work