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Build Scalable Payment APIs | Java Engineer (Mid)
| Location | Tokyo - 23 Wards |
| Job Type | Temporary |
| Salary | 6 million yen ~ 8 million yen |
Job Description
Join a high-impact engineering team building secure, scalable payment APIs used across a global digital ecosystem. You will contribute end-to-end across design, development, and operation of Java-based microservices in a fast-paced, collaborative environment.
Client Details
Our client is a large, globally recognized technology and internet services group operating a diverse digital ecosystem. Their platform division builds and runs the core infrastructure and payment systems that power multiple high-traffic services worldwide.
Description
- Design, develop, test, and deploy Java-based payment applications and RESTful APIs
- Contribute to scalable and secure microservices architecture
- Collaborate with engineers, product managers, and stakeholders to meet business needs
- Participate across the full SDLC, from requirements to production support
- Identify performance bottlenecks and improve system reliability and scalability
- Integrate third-party services and ensure secure data exchange
- Maintain and create technical documentation
- Conduct code reviews and follow best practices (Git, Agile, design patterns)
- Apply performance tuning and optimization techniques
- Continuously evaluate new tools, technologies, and engineering practices
Job Offer
- Opportunity to work on high-scale, real-world payment systems
- Collaborative, international engineering environment
- Exposure to modern microservices and cloud-native architectures
- Strong focus on security, performance, and best practices
- Career development within a large, tech-driven organization
To apply online please click the 'Apply' button below. For a confidential discussion about this role please contact Serena Wu on +81 3 6627 6137.
General Requirements
| Minimum Experience Level | No experience |
| Career Level | Mid Career |
| Minimum English Level | Fluent |
| Minimum Japanese Level | Basic |
| Minimum Education Level | Bachelor's Degree |
| Visa Status | Permission to work in Japan required |
Required Skills
- Experience as a Software Engineer with strong Java and SQL skills
- Hands-on experience with Spring Boot and Spring Framework
- Front-end fundamentals (HTML, CSS, JavaScript) for full-stack contribution
- Experience designing and developing RESTful APIs
- Knowledge of microservices architecture and best practices
- Understanding of secure coding and application security principles
- Experience with version control (Git) and Agile methodologies
- Familiarity with performance optimization and scalability techniques
- Exposure to AI prompt engineering or AI-assisted coding tools
- Experience with cloud platforms (e.g., AWS)
- Knowledge of Docker, Kubernetes, and container orchestration
- Familiarity with distributed tracing and monitoring tools
- Experience in e-commerce platforms or high-traffic systems
- Testing experience (unit, integration, performance)
- Open-source contributions or technical community involvement
Job Location
- Tokyo - 23 Wards
Work Conditions
| Job Type | Temporary |
| Salary | 6 million yen ~ 8 million yen |
| Industry | Software |
