PayPay Inside-Out People and Culture

Tech Talks vol.35 – Offline Mode Payment Project


About Tech Talks

In this Tech Talks series, we will share with you the attitude and vibe of the PayPay Tech Team through the voices of the unique product members from around 50 countries!
We spoke with five members of PayPay’s offline mode payment feature project.

PM: Dhruva Tanneru

Payments & Mini App Team, Payment Product Division

Hi, I’m Dhruva, Product Lead of Online Payments at PayPay. I have been with PayPay for about 4 years and was involved in expanding the Online Payments presence for PayPay in Japan!

Designer: Jonathan Chen

Manager, Payments & Mini App Team, Design Department, Payment Product Division
Payment Product Division Design Department Payment & Mini-App Manager

My name is Jonathan and I’m a designer at PayPay. I joined the company because I was attracted to the culture here where you get to work with people from different backgrounds.

iOS: Chiahsun Tung(Suin)

CoreApp iOS Team, Technology Department, Payment Product Division

I am Suin, and I work as an iOS engineer. I joined PayPay because it is a fast-growing company in Japan, where I wanted to work. Here I am blessed with many challenges and the opportunity to achieve fantastic results.

Android: Bobby Prabowo

CoreApp Android Team, Technology Department, Payment Product Division

Hello, my name is Bobby and I’m an Android engineer. I am grateful to PayPay for giving me the opportunity to work in Japan and in fintech, which is a totally new field for me.

BE: Kishore Nimmakayala

Payment Feature Team, Technology Department, Payment Product Division

I am Kishore, a backend engineer. PayPay is a multicultural company, and I like the fact that I get to be engaged in a product that numerous people use every day.

Please give us an overview of the offline mode payment project

I can’t give you the details because the patent is pending, but in July this year, we rolled out a feature that allows users to switch to offline mode payment and make a payment if there is no internet connection or weak internet to load the barcode.The project started in December 2022 and was successfully released thanks to the cooperation of 15 members of the Product Team as well as various members from risk and security management.

How did the project start?

We were aware through social media and app reviews that users were unable to make payments in crowded environments like at concerts or in underground restaurants. PayPay has 58 million users, Which means it is a social infrastructure given two out of three smartphone users have PayPay App.So we thought that it’s our responsibility to address these issues in our payment services and provide a seamless experience.

What was particularly challenging about your roles?

As a designer, I was focused on creating a seamless UIUX. For offline mode payments, it is important to provide a seamless payment experience while making users aware that they have switched to offline mode. Plus, users who are not tech-savvy should be able to use the system without difficulty. So, rather than adding new elements, we designed the system using existing components.

For frontend engineers, being involved with the home screen is already extremely challenging. In addition to the fact that it is a screen that everyone uses, the code is very complex because it is packed with many things and includes code written many years ago. We also had to consider various edge cases and legacy codes as we incorporated online and offline mode payment modes into one screen. In addition to preparing many of the test cases myself, many team members helped me decipher the logic of the code, and the QA Team provided immense support. Thanks to them, we were able to complete the project.

Since it was my first time to be involved in changing the home screen, I got advice from Suin and support from the QA Team to deal with the edge cases. Also, there was no network detection function to begin with, so we had to start from there. Being able to make that work was a game changer.

With one-time codes being so restrictive, and issues such as what can be changed at the barcode level and how to use the same barcode online and offline, the big question was what technical flow was secure enough for us to adopt. Also, in the actual implementation, one major technical difficulty was enabling the generation of an unlimited number of offline barcodes.

As for the technical flow that Kishore mentioned, after discussions with various members, we adopted the most secure and user-friendly option. Another challenging matter for me personally was to balance risk limitations and user needs. Currently, offline mode payments are limited to a maximum of 5,000 yen per transaction and two transactions per day for risk reasons. In determining these settings, we checked the average spend and frequency of use to ensure that users can pay with our system securely without impacting the user experience.

What were the key points you focused on during development?

Other than a robust security, which is a given, we heavily focused on providing a seamless payment experience to satisfy users. We had a very hard time making it discoverable so that users would be aware that they could make a payment even when they were offline.

To achieve this, we tried to keep the design simple and easy to understand, without cramming in too much information.

From a frontend perspective, we focused on stability. It is not enough to have a smooth transition from online to offline. We thought it was important to ensure that if the connection is restored, we get them back into online mode.

How have users been reacting since the rollout?

The launch went well and many users are actually utilizing it. The offline mode feature is of course only used when the internet connection is not good, but it has already been used by 3 million users in a month since its release.

It was all over social media and the news. I was so happy to see users reacting positively to this feature. It is very rewarding to see that my design is working well and making users happy.

When I saw my friends and neighbors actually using offline mode payment when they were out at a fireworks festival and had no internet connection, I so wanted to brag about it.

As a means of payment, it is significant to address situations where there is no internet connection. The user does not have to worry about their connectivity and only has to worry about whether they have enough balance.

In terms of being the industry’s first offline mode payment feature in Japan, this will also be a major differentiator from our competitors.

Yes. I recently read an article about how PayPay offline mode payments were helpful during unstable connections and huge lines at food and beverage stands at a summer outdoor event. Reading the article made me realize that PayPay is already an infrastructure rather than just a payment tool, and I am proud to be a member that brought this functionality.

What do you want to try out next at PayPay?

I want to continue improving the offline mode payment feature, like improving on areas where there are limitations. I also want to communicate with and educate users to make their lives easier.
I’m sure there are cases where offline mode payments have been quite useful and some cases where it was subpar. So I think it is important to analyze these cases and fix those areas that we’ve overlooked.

I hope we can make the payment process smoother. For example, if a user goes to a convenience store, and the app can recognize the store and even the available payment methods, the user would only have to choose which payment method to use. I think that kind of improvement is a possibility.
Outside of this functionality, I would like to make PayPay an open platform and continuously expand the possibilities it can offer since it can be a hub for a variety of services. This can lead to both business opportunities and personal growth.

I am currently mainly involved in offline mode payments, but I would like more users to use PayPay and I also want to pursue providing further convenience and stability. It would be nice to see users utilize a system that is stable and convenient, whether it be online purchases or in-store scans.

I am currently in charge of online payments,I help expand PayPay’s Online Payments presence in Japan and also build Payment features to make the entire payment experience seamless for the users.

In my case, I am currently working on a home screen revamp project. We’ve been using the current home screen for about two years since it was designed, so it is about time to renew it. It is a significantly challenging project as we are dealing with the central feature of the app that all users pass through, so I will focus on that first.

Finally, any words for job seekers?

PayPay is increasingly tackling new areas such as online payments and will continue to explore new markets. Being involved in projects that have such an impact on society is a major attraction of PayPay. If you are looking for an exciting experience solving tough problems, come work with us.

I think there is nothing more rewarding for engineers than seeing the features they have developed actually being used. You can see PayPay being used anywhere in Japan, and being part of its development is a unique experience. If you want to be involved in a product that many people are fond of using, I would encourage you to apply to PayPay!

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*Recruitment status and employee affiliations are correct at the time of the interview.