About PayPay Card PayPay Card Corporation was established in 2021 to provide users a FinTech service that is more accessible and convenient compared to previous credit cards and credit services, by integrating with the PayPay payment platform, which has surpassed 70 million users since its launch (as of July 2025). We are looking for people who are passionate about refining our products at an overwhelming speed that other companies cannot match, as well as professionals who are interested in promoting the spread of cashless payments in Japan and the use of these payments as a financial life platform. Let us work together to create new value for users.

※ Please note that you cannot apply or be selected in parallel with PayPay Corporation, PayPay Card Corporation and PayPay Securities Corporation. Job Description We are looking for backend engineers to build, or rebuild, rock solid services with a laser focus on scalability and maintainability. PayPay Card aims at revolutionizing the credit card industry, making payment easier than ever, from two different angles: Bring the credit card experience to the next level: we have many functionalities in the pipe to improve our product, not to mention the integration into the PayPay ecosystem as PayPay Card is part of the PayPay Group.

(Re-)architect our systems landscape: we want to reassess and fix the behind-the-scenes to power a top-notch user experience. It is bundled with difficult design challenges to solve: we simply want to get it right. As a fast-paced company leading the payments industry, we need our engineers to be versatile and enthusiastic to take on new challenges in order to stay at the forefront.

Indeed, we strive for continuous improvement within our systems as well as outside our systems. Additionally, we value communication, to smoothly cooperate with other teams, and inclusivity, to efficiently navigate in a multicultural environment.

Responsibilities

Support the design, implementation and delivery of large scale, and complex, systems, while collaborating with product managers, frontend engineers or other team members. Understand how to leverage infrastructure to solve large scale problems. Contribute to the team by sharing knowledge, participating in code reviews and providing feedback to uphold and ensure best practices.

Triage, debug and resolve product issues or other incoming troubles inquiries Adopt problem solving as a way of life – always go to the root cause! Support the code you write in production. Tech Stack We currently work with Back-end services: Main implementations are in Spring Boot, with a mix of Java 11/Spring Boot 2 and Java 17/Spring Boot 3.

Some legacy systems are written in Java EE. Testing is done with JUnit and Mockito Deployment relies on AWS ECS CI/CD is handled by AWS CodePipeline Infrastructure All our services run in AWS Infrastructure is managed by AWS CloudFormation AWS CloudWatch is used for observability Coding environment: GitHub, IntelliJ, Gradle Documentation Project management: Confluence, Miro, JIRA Communication: Slack, Zoom, Office 365 Please note that PayPay Card is challenging its current architecture, potentially introducing new technologies and/or deprecating existing ones.

Required Qualifications

Skills in OOP language such as C# or other JVM language, such as Scala are welcome Experience with RDBMS, NoSQL databases along with distributed cache. Strong fundamentals in data structures, algorithms and object oriented programming. In-depth understanding of concurrency and distributed computing.

Experience implementing platform components such as RESTful APIs, Pub/Sub Systems, and Database Clients. Experience with microservices and event-driven architectures. Experience designing high traffic systems.

Degree in Computer Engineering or Computer Science or 3+ years equivalent experience in SaaS platform development.

Preferred Qualifications

Domain-driven development knowledge Java/Spring Boo

Backend Engineer