This position is closed and is no longer accepting applications.

Product Security - Application Security Engineer

PayPay Minato-ku, Tokyo
    💴 ¥7M ~ ¥14M annually
    🏡 Fully remote
    🧪 3+ years experience required
    💬 No Japanese required
    🌏 Apply from abroad
    🧳 Relocate to Japan

About PayPay

PayPay Minato-ku, Tokyo

With over 55 million registered users (as of February 2023), PayPay is the country’s most popular mobile wallet. Half of all of Japan's smartphone users are using it, and more than 2 billion payments made per year.

Key benefits

  • International engineering team
  • Japanese lessons on company time
  • Incredible scale

About the position

The PayPay Product Security team is seeking Application Security (AppSec) engineers to work with our development teams on maintaining the security of our services.

PayPay Product Security team is responsible for driving the application security and infrastructure security changes within the product division - the part of PayPay responsible for development and operations of the PayPay app. Specifically AppSec engineers focus on supporting our development teams through discovery, knowledge sharing and the automation of security configuration, testing, verification and monitoring. A strong candidate for AppSec engineer will have a good understanding of software security best practices as well as an understanding of how to apply those principles to systems at scale following the DevOps methodology.


  • Working closely with Security Champions and teams on implementation of security best practices
  • Supporting development teams throughout Secure SDLC (design and architecture review, code reviews, manual security assessments)
  • Introducing systemic improvements to software security at PayPay (automation, processes, guidelines, secure libraries)
  • Maintaining up to date knowledge of security best practices
  • Assist threat modeling of existing and upcoming products and systems
  • Training and mentoring of PayPay staff on security best practices and its practical application
  • Maintaining automated systems to assist teams with assessing current security status
  • Working in a fast paced environment where projects and prioritization may change frequently but maintaining a secure product is a requirement for all team members


  • 3+ years of product security experience
  • Experience leading projects tasked with improving product security and/or DevOps security
  • Strong teamwork skills and the ability to collaborate with others in a diverse environment
  • Enjoy taking up a challenge and driving it to conclusion
  • Have excellent written, verbal and interpersonal communication skills.

Nice to haves

While not required, tell us if you have any of the following.

  • One or more of Javascript/Typescript, Kotlin, Scala and Java
  • Experience with securing Android and iOS Applications
  • Experience with microservice-based and cloud-native applications
  • Experience working in a security position within the fintech industry
  • Bilingual in English and Japanese


7 to 14 million JPY annually.

Meet PayPay's Developers

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iOS Development at PayPay

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Yoseph joined PayPay after being attracted to their mission of making Japan a cashless society. As an iOS Engineer, he originally joined their iOS feature team, but now works on their platform team, creating an internal SDK for their iOS and Android apps.

Read his story...

Shilei started working on PayPay before it launched, and has seen it grow into a product used by tens of millions of users. He explains how diversity has helped them overcome challenges, and what PayPay is looking for in candidates.

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Refactoring PayPay’s Android App

with Adrian Mariadas

Adrian came to Japan to join PayPay as an Android Engineer. As the app has grown in scope, refactoring the codebase to ensure development can continue at a rapid pace has been a big part of his job.

Read his story...

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