Senior Backend Engineer

Job Type
650,000 JPY - 800,000 JPY per month
Japanese Level
English Level
Advanced (TOEIC 860)
Start Date


One of the world's leading Internet services companies, providing a variety of consumer and business-focused services including e-commerce, eBooks & eReading, travel, banking, securities. In addition, they has been recently established, delivering the world's first fully virtualized Mobile Network, which will also support the most diversified IoT solutions. Our team is focused on establishing the building blocks to empower society through IoT innovations.


Our Group:

The IoT Technology Section is the engineering arm of their IoT Business Department. Our mission is establishing a pervasive ecosystem of platforms and solutions to help deliver IoT innovations with productivity, strong security and connectivity. Of course, we also deliver our own IoT end-to-end solutions.


About the working environment:

You will work on a team with people from diverse cultures and backgrounds (currently 7 distinct nationalities within our team and over 70 on their Group),

Friendly and open working environment and English is our official working language.


【Main Responsibilities】

- Design and develop backend systems for K8s environment

- Ensure backend systems have no single point of failure and are ready to scale on demand

- Write well-documented, testable code

- Maintain high unit test coverage of your own code

- Write interactive documentation for your API's (using swagger)

- Work together with DevOps team to automate your application's CI/CD pipelines

- Work together with DevSecOps teams to achieve requirements for production deployment and operations handover


【Secondary Responsibilities】

- Provide L2 support for troubleshooting and solving issues when they cannot be worked around by L1

- Support and mentor younger members on their career development as a backend engineer

- Collaborate with offshore teams on software development


【会社概要 | Company Details】

A growing mobile carrier company as a forth MNO (Mobile Network Operator.) to become the No. 1 MVNO in Japan.

【就業時間 | Working Hours】
9:00 - 17:30(月 - 金)
【休日休暇 | Holidays】

Saturday, Sunday, and National Holidays, Year-end and New Year Holidays, Paid Holidays, Other Special Holidays
【待遇・福利厚生 | Services / Benefits】

Social insurance, Transportation Fee, No smoking indoors allowed (Designated smoking area), etc.



Required Skills

The ideal candidate will be an experienced IT software engineer with extensive experience on highly available, high throughput backend systems development. You will be expected to design cloud-native API services, integrate security, guide application networking requirements, design for high availability and horizontal scalability. You will also plan your application monitoring and servicing capabilities for auto-scaling, nearly zero-downtime upgrades and so on.


Required Qualifications:

- Education on Engineering or IT related field

- Experience on Software Development

- Experience on Backend Systems development

- Experience with Java development

- Experience developing RESTful API's

- Experience with Docker

- Experience with SQL & NoSQL databases

- Able to design backend systems end-to-end by yourself

- Able to learn and adapt to new technologies

Preferred Skills

- Experience developing for Kubernetes

- Experience with Reactive Programming

- Experience with messaging queues (preferably Kafka)

- Experience with designing API's to support bulk requests

- Experience with Hardware Security Modules and Key Management Systems

- Experience interfacing with PKI

- Experience with OpenID and Oauth2.0

- Experience with authentication via Smart cards

- Business Level communication in Japanese