Senior Backend Engineer (Principal / Tech Lead)

  • Full Time
  • Tokyo (Remote)
  • 14,000,000 - 18,000,000 JPY / Year

Website PayPay

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

PayPay is seeking a skilled Senior Backend Engineer (Tech Lead) to enhance our payment system, ensuring an optimal payment experience for our customers.


  • Design and develop large-scale systems to support high throughput applications with complex requirements.
  • Utilize infrastructure effectively to address scalability challenges.
  • Contribute to open source projects and develop tools to improve system efficiency.
  • Embrace problem-solving as a core practice, focusing on root cause analysis and providing ongoing support for production code.


  • Proficiency in Java or equivalent programming languages (Scala, Python, Go).
  • Eagerness to learn new languages and technologies as required.
  • Experience with SQL and NoSQL databases, as well as distributed caching.
  • Strong understanding of data structures, algorithms, and object-oriented programming principles.
  • Knowledge of concurrency and distributed computing.
  • Hands-on experience with RESTful APIs, Pub/Sub Systems, and Database Clients.
  • Familiarity with microservices architecture.
  • Previous involvement in designing and maintaining high-traffic systems.
  • Bachelor’s degree in Computer Engineering, Computer Science, or equivalent experience in SaaS platform development (minimum 5 years).

Nice to haves

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

  • Previous experience in developing new products from inception.
  • Ability to design systems compliant with legal and security standards, with strong leadership skills for requirement identification.
  • Experience in improving system resilience and implementing disaster recovery strategies.
  • Awareness of market trends and needs, prioritizing speed and quality through MVP approaches.
  • Track record of delivering products within tight deadlines.
  • Commitment to continuous product improvement post-launch.
  • Strong cost-efficiency mindset with effective system cost analysis skills.
  • Willingness to share experiences and foster a culture of learning and improvement.
  • Experience in finance, payment, or related industries.
  • Language proficiency in Japanese.
  • Experience with AWS services.


14 to 18 million JPY annually.

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