Senior Software Engineer-Core API (EC)

Job Type
6,000,000 JPY - 8,000,000 JPY per year (negotiable based on experience)
Japanese Level
English Level
Advanced (TOEIC 860)
Start Date


Exciting opportunity to work at one of the top internet service companies which has millions of users and some of the most popular Internet services in Japan today. These services are expanding all over the world!


【Position Summary】

The Senior API Engineer will collaborate with architects, product managers and software engineers to influence the product direction and functional requirements, and deliver APIs. This position requires self-motivated people with the ability to design and develop high-performance, reliable, and maintainable code. This is your chance to build and maintain Core APIs for a service reaching out to millions of users worldwide.



‐Design and program simple and readable codes

‐Make a unit test with high coverage rate

‐Design and build a high performance, high availability, high scalability APIs

‐Review a design and code made a good quality and system as a platform

‐Make a good solution to fix bottleneck

‐API documentation

‐Research and learn new technologies to make good design and solution

Required Skills

‐Java development experience

‐Experience building RESTful API

‐Experience using modern framework (Play framework, Spring Boot)

‐Experience using NoSQL (Apache Cassandra, Couchbase, etc)

‐Experience using In-Memory Cache Technology (Redis)

Preferred Skills

‐E-Commerce business domain knowledge (B2B, B2C or both)

‐Experience of develop and operate large scale web-based system

‐Awesome programming skills, concurrent and reactive(asynchronous with observable streams and event based) programming

‐Experience using API documentation(Swagger)

‐Experience Agile Scrum development cycles

‐Experience CI/CD delivery cycles

‐Applying unit testing / Using TDD to write well-tested code

‐Applying and developing more automation

‐Reading and contributing for Open Source Software