PayPay Inside-Out People and Culture

Platform Engineer – The Backbone behind PayPay Transaction


Professionals at PayPay

【Professionals at PayPay】 is a running story that introduces the outstanding professionals who support PayPay

Karan Thanvi

Product Division

The backbone behind the explosive growth of PayPay’s transactions

-First of all, please tell us about the work you do at PayPay.

I am responsible for the development and maintenance of the general payment platform at PayPay. Since the number of users and payments increase exponentially every day, my job is to support a stable operation of PayPay with the goal of improving system scalability. I am responsible for a wide range of backend areas such as managing AWS self-managed Kubernetes and AWS service provisioning. We are also working on building a new technology stack, such as building TiDB on Kubernetes and implementing Argo CD.

– You are truly the backbone behind PayPay. How did you get started in your engineering career?

I studied programming at an Institute of Technology in India and participated in an internship as an engineer while I was a student. In the first company I was at, I developed a TIZEN OS application, and at the next company, I worked on the backend development of security solutions. At the former, I worked in a small team where interns were empowered with ensuring quality, and that was where I realized the joy in bringing things out into the world. At the ​latter, I was surrounded by experienced and talented senior colleagues, where I learned the joy of working under pressure.

Aspiring to work in a Japanese company and facing reality

-What career path did you choose after graduating from university?

While pursuing a path to become an engineer in India, I always had the dream of exploring technology across the globe. Although ​I received several offers from global companies, I chose to work for a Japanese technology company, as I wanted to follow my interest in Japan’s advanced technology, Japanese culture and politeness, and the “Toyota-style KAIZEN (improvement) process” that I was reading about at the time. I wanted to see with my own eyes how the theories I read in the book were applicable in the real world, and how they contribute to the growth of a business as well as individual capabilities.

-How was your experience working for a Japanese company ?

When I first came to Japan and joined the company I experienced a gap in my and the company’s values. For example, the work hours were tightly controlled, workstations were fixed, etc. The way I see it is the engineers can dramatically improve work efficiency if given more freedom and independence. Also, as an engineer, I’m always looking for ways to incorporate new technology and the latest architectures. I don’t want to have to compromise my standards because of companies continuing to use legacy systems.

A shocking encounter and the words that captured my heart

-Was it that gap that lead you to PayPay?

In fact, I have been following PayPay since around December 2018. The all too shocking “10 billion yen campaign” made me realize that PayPay is serious about promoting the cashless system in Japan, and I thought I could play a role in social innovation if I joined the company.

But the main reason I absolutely wanted to work at PayPay was because I saw ​Aditya Mhatre’s (Product Division Manager) Video. He talked about the importance of communication to achieve results in a rapidly changing environment. I was completely captivated by the words, “Communicate, Communicate, Communicate!”

I then created a LinkedIn job search filter to keep an eye on PayPay job listings and frantically searched for jobs that contained the keyword “PayPay”, but there weren’t any suitable position immediately available. However, I was determined to meet someone from PayPay and ask around about the technology stack, so I decided to apply for a different position.

In an interview with Shilei Long (Technology Manager, Product Division), I learnt that PayPay designed their system with a microservices architecture and used advanced technology, and in the subsequent interview with Aditya, he explained that PayPay’s back-end system always applies the latest technology. That was the moment I decided to join PayPay.

An open environment and a time of great learning

-How do you feel about having joined PayPay?

Before I joined the company, I wasn’t sure if I would fit in and be able to communicate well with the team members, but as Aditya emphasized in the video, communication was very open in PayPay. I was also surprised that he gave me the freedom to choose any technical area or project I wanted to work on from my first day. .

One day, the HR team created a member tree and a map of countries of origin and put it on the wall. When I saw the tree with all the photos of our hard working members, their country of origin and messages, I felt really happy and excited to be part of such a wonderful team.

PayPay famous member tree and diversity map

-What were some of the difficulties you faced at work?

The work was honestly very hard because the technology PayPay uses is cutting edge. At first I wasn’t sure if I could keep up, but I grew accustomed to the excitement of learning about new technology. I was so enthralled and immersed in the project that I forgot I was working long hours. I realized that this was the environment I had been looking for. Working overtime in PayPay doesn’t mean overtime, it means a time of great learning, at least for me! (laughs).

In such a challenging environment, my first task was to migrate the most important microservice, Payment, to TiDB is the latest database technology, which I had never heard of before.

The project was very demanding, but thanks to that, I was able to learn about advanced database concepts such as Kubernetes, helm, terraform, ansible, and also implemented the Prometheus stack in the production environment to deploy a monitoring system. It was a great feeling when the migration was completed much faster than the time we had set.

The project members who survived the TiDB project! (Karan is the fourth person from the right)]
Cakes to celebrate TiDB migration success

-It sounds like a very rewarding experience.

Yes, it was. All of these are experiences are unique to PayPay. My Japanese skills have also improved since I joined the company. I am grateful of everyone who has to cope with my broken Japanese and also to PayPay’s Japanese language classes (laughs). We also use many open source software tools at PayPay, so I think I became more knowledgeable about OSS and improved my ability to add functions to existing software and fix bugs.

-It’s like killing two birds with one stone – technology and Japanese (laughs).

Whenever I meet my mentors and seniors, they always give me two compliments. One is, “Karan, you have really improved your skills” and the other is “Your Japanese has improved.” I answer “I still have a long way yet”, but I’m still really happy to hear that (laughs).

A dream to work for the benefit of society

-Finally, please tell us what you want achieve with PayPay in the future.

As the largest mobile payment provider in Japan, our goal for the coming year is to improve the scalability of the payment platform. Over the next three years, we will make the PayPay platform more flexible and easier for merchants to integrate with.

Also, the biggest reason why I joined PayPay is to work for the benefit of society; to create a big system that supports people and society in critical situations such as typhoons, tsunamis, earthquakes, COVID-19 pandemics, etc. In the medium to long term, I would like to become a leader of a PayPay project that focuses on social support.

Furthermore, PayPay adopts many open source technologies which are an essential to the PayPay platform today, and I think it is wonderful that PayPay contributes to the benefit of everyone in the technology community.

Thank you Karan!

Currently available positions

Thanks to:
Karan Thanvi – Platform Team, Product Division

Editing: az (PayPay Inside-Out editorial department)
​ ​*Employees’ affiliations are as of the time of the interview.