PayPay Inside-Out People and Culture

Tech Talks vol.13 – iOS Engineer


About Tech Talks

In this Tech Talks series, we will directly share with you the attitude and vibe of the PayPay Tech team through the voices of the unique product members from approximately 40 countries! This time, Suin from the Consumer iOS Team will share his story.

*The Japanese version of the article is also available here.

Suin (Chia Hsun Tung)

Consumer iOS Team

I joined PayPay on March 3, 2020. During the approximate two years since then, I’ve been involved in the development of the iOS app for consumers, and am currently the Tech Lead of the iOS Team.

What I currently do

As an iOS engineer, my main job is to develop new features and fix bugs. PayPay has a very open atmosphere for developers and continuous improvement is part of the corporate culture, so everyone has the opportunity to participate in the development of features and to voice their opinions. During my time at PayPay, I’ve developed many features such as the flip card on the home screen and widgets features. I was fortunate enough to get promoted to Tech Lead in the recent past, so now I participate in more meetings. One of my key tasks in this role is to focus on the development process and architecture.

A technical challenge I experienced recently

In my previous job, everyone had ideas, but were usually reluctant to implement them because they were afraid of changing too many things. At PayPay, on the other hand, we go ahead with changes we want to make without holding back.

A few months ago, I was working on getting the coverage of unit tests up to a certain level. The biggest challenge was that the existing architecture was incapable of performing full unit tests and required significant changes. The first step towards that was to develop an architecture that would allow for full unit tests, which meant investing a lot of manpower and time to refactor the current program. After repeated reviews and discussions, we gradually defined the architecture, rebuilt the program, and used DI to write tests (making such a drastic change to an app with tens of millions of users was a lot of pressure). Next, in order to avoid bugs, we established a set of development and testing processes, which enabled switching between old and new codes for a smooth migration. The success was thanks to the developers who invested a lot of time in rebuilding to achieve this goal, coupled with the help of a reliable testing team.

What challenges I want to take-up at PayPay

I’m eager about tweaking our development process and architecture, as well as developing more interesting and convenient features.

My typical daily & weekly schedules

Usually, I start my work at 10 a.m. I can work from anywhere in Japan, so the time I get up is not too important. If I want to go work in Shibuya, I get up earlier. The first thing I do in the morning is to determine my schedule for the day. Remote work has led to many meetings where we discuss a bunch of details. As for the App Team, we have a sync up meeting every day, and after that we start doing code reviews or pull requests (PR). Due to a large team, numerous PRs queue up for review every day. After going through them, I move on to my backlog to start developing features or fixing bugs. Meanwhile, I also always keep an eye out for any iOS-related questions or bugs on Slack that I’m capable of addressing. Now that I’m the Tech Lead, I also spend some time thinking about whether there is any room for improvement in the app.

One of the interesting things about iOS development is that we release new versions every week. That means we only have limited time each week for development, implementation, testing, and product launch. This makes every day a very tight but fulfilling day.

Our team has weekly sharing sessions. In this session, everyone can share a new feature or new knowledge recently discovered, not limited to iOS. You can also publish the knowledge of engineers for everyone to learn, and you can also discuss the development structure, process, testing, etc. of the product.

We also sometimes choose a day for the entire team to work together at the WeWork office. After we get off work, we usually chat and drink the free beer. It’s great to get to know each other better.

My career before joining PayPay

PayPay is actually my first Japanese company. Before coming here, I worked in various fields. I was responsible for developing ERP systems specially developed for enterprises, or the development of the largest app in Taiwan’s stock market and financial sector, as well as having some experience in the world’s largest dating app for the LGBT people.

The reason I decided to join PayPay

Mainly due to my frequent travels to Japan, during which I often saw PayPay logos in various stores. Also, as an iOS developer, it gives me a sense of accomplishment to see that my app is used by many people and that my products are convenient for numerous users. So, I would add that another big factor was PayPay’s very high penetration rate and large number of users in Japan.

It’s worth mentioning that the development department of the company is made up of people from diverse countries, and I can work with excellent people from various backgrounds. Every day, employees can learn about different ideas and experiences, face multiple challenges, and enjoy a sense of achievement.

On top of all this, employees can work freely in various locations, which is very convenient for me as I like to travel. I can choose where to work according to the mood I’m in. For example, I can work from a ski resort during ski season. I’ve also been to more than a dozen WeWork offices in Tokyo.

A message to aspiring PayPay employees

AYou have the opportunity to develop an app that has tens of millions of users in Japan, not to mention the app is a constant contender for the number one spot in the app store ranking.

You are free to decide where you work each day depending on how you feel, the season, and travel plans (every time I work in a different location, what makes me happiest is finding food from different regions).You also get to work with people from different countries and cultures.

In PayPay, there are many interesting things and challenges waiting for you, and you can get a huge of sense of accomplishment every day. Remember, you can develop the app that is now changing Japan. We welcome anyone with great ideas to join us!

Currently available positions

Author: Suin / Editorial Supervisor: Mune / Managing Editor: Az
*Employees’ affiliations are as of the time of the interview.