Software Engineer for Consumer Finance Engineering


About Paidy Inc.


Paidy was founded with the mission to create a world of “We remove the barriers, embrace simplicity”, offering its real-time monthly consolidated credit service all across Japan.

Paidy started Japan’s first instant post-pay credit service for ecommerce consumers in October 2014. Paidy requires no pre-registration or credit card to use; Paidy consumers purchase products online using only a mobile phone number and email address (verification is established though a four-digit code via SMS or voice pin-code) and settle a single monthly bill for all their purchases, either at a convenience store, by bank transfer or auto debit. Paidy also supports multi-pay installments and subscriptions. There are currently over 3,500,000 Paidy accounts in use (July 2020). Paidy has proved a powerful means of persuading first time buyers to transact online. Its proprietary models and machine learning

mean that transactions are underwritten in seconds, with guaranteed payment to merchants.

Paidy increases merchant revenues by reducing incomplete transactions, increasing conversion rates, boosting average order values, and facilitating easy repeat buying.

For more information visit


About Position:


This position is for a Software Engineer, reporting to the Consumer Finance Engineering Manager, who will help design and develop projects integrating with APIs for credit card integrations and other financial service products.  The position calls for an engineering role, meaning someone who can also lead projects from design to completion.

Our tech stack includes:

  • Docker-based microservices written in the Rust Programming Language
  • Other Paidy microservices written in Scala (outside the team, but have occasional interactions with these services in our team)
  • AWS Services (fargate, RDS, lambda) with PostgreSQL DB
  • Circle CI + terraform provisioning and deployment
  • Linux/MacOS development environment
  • HTTPS, SSL, X.509, and other secure technologies for secure communications
  • HTTP REST and GraphQL APIs (JSON data)
  • Kafka Message Queueing


Your Duties & Responsibilities:


* At least 3 years of backend development in multiple modern programming languages (C/C++, Java, Rust, Scala, Golang, Python, etc.)

* Experience with designing software both from the ground up and making changes to existing applications (OO-design, Microservices, functional design, DDD, Domain/Protocol separation, etc.)

* Knowledge of systems development and operations (Docker, Redis, SQL DBs, AWS, Source-control, CI/CD systems, etc.)

* Understanding of OO-design principles

* Understanding of functional programming paradigm and methodologies

* Business-level fluency or higher in English


The following are encouraged, but not required:

* Development experience with multiple programming languages

* Some knowledge of or experience with functional programming.

* Experience in the Fin-Tech industry, especially with banking systems and/or credit-card processing systems


Qualifications/Must Have

  • 3+ years experience with multiple backend programming languages
  • Business-level or higher English (both reading and writing) 
  • Prior Rust or Scala experience is NOT a requirement
  • Conversational fluency in Japanese is a plus (NOT required)
  • Understanding of software engineering principles (OO, Functional Programming, software design, etc.)

Please note that you must be eligible to work in Japan.


Paidy Value:


Candidates must be able to demonstrate affinity with the Paidy core values:

Be a winner  勝ちにこだわる

  • Beat expectations 私たちは、常に期待値を超える。
  • Display surprising speed 人をスピードで驚かす。
  • Embrace risk リスクを恐れない。

Own it and deliver  結果を出す

  • Commit to what, when and how to deliver 私たちは、目的・やり方・期限にコミットする。
  • Own the actions to deliver 結果のためのアクションにこだわる。
  • Embrace conflict when needed to deliver results 必要なら対立・衝突も恐れない。

Play an integral role  大切なピースになる

  • Make an irreplaceable contribution to our business 私たちは、替えの効かない貢献をする。
  • Embrace and bridge differences in language and culture 皆が言語と文化の架け橋になる。
  • Raise the bar スタンダードを上げ続ける。