Senior Software Engineer, Payment Connections

  • Tokyo, Japan
  • Full-time

Company Description

Square builds common business tools in unconventional ways so more people can start, run, and grow their businesses. When Square started, it was difficult and expensive (or just plain impossible) for some businesses to take credit cards. Square made credit card payments possible for all by turning a mobile phone into a credit card reader. Since then Square has been building an entire business toolkit of both hardware and software products including Square Capital, Square Terminal, Square Payroll, and more. We’re working to find new and better ways to help businesses succeed on their own terms—and we’re looking for people like you to help shape tomorrow at Square.

Job Description

The Payment Connections team enables Square to move money globally by building highly reliable channels to payment networks and acquirers. As a Senior Software Engineer, you will build features and applications that power Square’s global expansion. Your work will empower the coffee shop down the street and the website on the other side of the planet to focus on their core business, not on their payments. 

You will:

  • Work on a team that has its hand in projects impacting payments around the globe.

  • Dive into the specifications and systems of the incumbent financial world and find ways to abstract them into consistent, coherent features for Square’s modern payments platform.

  • Work with talented teams across Square (including a sister team in Atlanta, Georgia, USA) to translate what’s possible into remarkable experiences for our sellers and their customers.

  • Own features and integrations throughout their lifecycle, from initial design to production payments.

  • Work with the full lifecycle of JCB, eMoney payments as well as international payment brands.

  • Build systems that are maintainable and well-tested.

  • Own systems that move billions of dollars, pounds and yen every week.


You have:

  • Fluency in both Japanese (Native or JLPT-N1) and English.  You will need to be able to read and write specifications and business correspondence in Japanese as well as engineering documentation and written and verbal communication in English with your counterparts outside of Japan.

  • An innate curiosity about how money moves, and the desire to become an expert in financial systems.

  • A willingness to lean into understanding complex systems and how they could be better.

  • Strong interpersonal skills and the willingness to collaborate with both a local team and counterparts in remote offices.

  • 5+ years of industry experience.

Technologies we use and teach:

  • Java

  • Protocols such as ISO8583 and AS2805

  • Deploy code to GCP, AWS, and Square's data centers

  • Guice, Guava, Protocol Buffers, gRPC, Envoy

  • MySQL, Kafka, SignalFX, Spanner, BigQuery

Additional Information

At Square, our purpose is to empower – within and outside of our walls. In order to build the best tools for the businesses and customers we support all over the world, we have to start at home with a workforce as diverse and empowered as our sellers. To this end, we take great care to evaluate all employees and job applicants equally, based on merit, competence, and qualifications. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, disability status, or any other characteristic protected by law. We encourage candidates from all backgrounds to apply. Applicants in need of special assistance or accommodation during the interview process or in accessing our website may contact us by sending an email to assistance(at) We will treat your request as confidentially as possible. In your email, please include your name and preferred method of contact, and we will respond as soon as possible.


At Square, we want you to be well and thrive. Our global benefits package includes:
  • Healthcare coverage
  • Retirement Plans
  • Employee Stock Purchase Program
  • Wellness perks
  • Paid parental leave
  • Paid time off
  • Learning and Development resources
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