Job Description:Department OverviewEC Marketplace Development Department (ECMPD) is a tech division under Commerce & Marketing Company of Rakuten Group, Inc. We are responsible for developing and enhancing our online system to support our core business, Rakuten Ichiba. Rakuten Ichiba is one of the largest internet shopping malls in Japan with 5.6 trillion sales in 2022 and our business is growing year on year. We aim to provide the best shopping entertainment for our shoppers and empower our partners in Rakuten Ichiba. Position:Position DetailsOur team is responsible for the design, development, and end-to-end lifecycle management of high-availability backend and frontend services for Rakuten Ichiba’s vital "Reserve" and "Repeat Purchase" systems. As one of the core services of Rakuten Ichiba, our services directly influence the shopping experience for millions of customers. We are looking for a passionate and innovative engineer to join our team located in Osaka. You will not only build scalable features for these mission-critical systems but also take ownership of the full-service lifecycle - from architecture and development to troubleshooting and operational excellence. We value engineers who bring fresh perspectives, thrive on solving complex technical challenges, and collaborate proactively to deliver the best shopping experiences at scale. If you are eager to drive innovation in one of Rakuten’s most important e-commerce systems and grow within a dynamic, high-impact environment, we invite you to join us.Mandatory Qualifications:- More than 10 years’ experience in software design & development. - More than 5 years Java/Java EE (Deep understanding of JVM internals: GC, memory, class loading). - Design/Dev of RESTful APIs & Microservices. - Strong understanding of SDLC (Code standard & peer review, SCM, testing) & bring best practices. - Experience with Docker/Kubernetes, CI/CD (e.g., Jenkins), and system monitoring. - Experience in 24/7 system maintenance, monitoring, and troubleshooting. - Experience in driving system improvements and modernization within the constraints of existing legacy environments. - Proven track record of understanding business requirements and delivering high-quality features with speed and agility. - Ability to drive system evolution (refactoring, architecture, performance tuning). Desired Qualifications:- Experience in application development using Spring Framework. - Design and development experience with RDBMS, KVS, & NoSQL. - Proficiency in React. - Prior experience in technical leadership or team management. - Ability to leverage AI tools (e.g., Claude, GitHub Copilot) to enhance development productivity. - Deep understanding and practical experience with both Waterfall and Agile methodologies. - Experience in traffic management using CDNs and advanced caching strategies. - Experience implementing GraphQL, JSON-RPC, or gRPC; proficiency in middleware (e.g., Apache, Nginx, Tomcat). - Expertise in configuration management (Git, Maven, Gradle) and advanced Linux/GNU troubleshooting. - Knowledge of best practices for financial systems (e.g., currency handling, precision, traceability). - Experience in designing, developing, and operating large-scale e-commerce systems. Other Information:Additional information on LocationOsaka BranchSumitomo Nakanoshima Building 8F, 3-2-18 Nakanoshima, Kita-ku, Osaka City, OsakaAdditional information on English QualificationTOEIC Score 800 above or possess equivalent abilities#engineer #applicationsengineer #commerce #RakutenIchiba Languages:English (Overall - 4 - Fluent), Japanese (Overall - 2 - Intermediate)