Senior AI Agent Engineer - AI Agent Development Section, Business Support Development Department (BSD)
On-siteTokyo, Tokyo, Japan
Tokyo, Tokyo, JapanOn-siteFull TimeSenior LevelEnterprise
Full TimeSenior LevelEnterprise
Job Summary
Design and develop autonomous AI agents using LLMs and agentic frameworks to build next-generation solutions for Rakuten's diverse business units. Build tool-use capabilities for agents to interact with external systems and databases, while optimizing workflows for reasoning, planning, and task execution accuracy. Evaluate and refine agent performance through rigorous testing and prompt engineering. Requires 7+ years of hands-on experience in web application design, Java (Spring Boot), and large-scale system operations. Located in Tokyo.
Required Qualifications
- 7+ years of hands-on experience in web application design, code reviews, performance tuning, and architectural improvements
- 7+ years of experience in application development with a focus on database schema design and integration with external systems
- Extensive hands-on experience (7+ years) in the design and development of Web APIs
- 7+ years of experience in the development and operation of large-scale systems using Java (Spring Boot)
- Experience with LLM orchestration frameworks such as LangChain, LlamaIndex, CrewAI, or Microsoft AutoGen
- Understanding of Prompt Engineering and Chain-of-Thought (CoT) reasoning techniques
- Professional working proficiency in Japanese or higher
- TOEIC score of 800+ or equivalent business-level English proficiency
Desired Qualifications
- Experience of management for large scale projects
- Experience in evaluating agent performance using automated testing frameworks
- Knowledge of LLM performance optimization (latency reduction, cost management)
Hiring someone like this?
Get your role in front of qualified candidates on Sorce.