Lead Software Engineer, Rakuten Ichiba - EC Marketplace Development Department (ECMPD)

Job Description: Department Overview EC 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 Details Our 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 English Qualification TOEIC Score 800 above or possess equivalent abilities #engineer #applicationsengineer #commerce #RakutenIchiba Languages: English (Overall - 4 - Fluent), Japanese (Overall - 2 - Intermediate) In Japanese, Rakuten stands for ‘optimism.’ It means we believe in the future. It’s an understanding that, with the right mind-set, we can make the future better by what we do today. So we challenge ourselves to evolve, innovate and experiment, to create a better, brighter future for everyone. Today, our 70+ businesses span e-commerce, digital content, communications and fintech, bringing the joy of discovery to almost 1.3 billion members across the world. If you have any trouble logging in, please contact us here Rakuten Group, Inc.: rakuten-recruiting-info@mail.rakuten.com Please read the Application Requirements(EN) / 募集要項(JP) before applying. Our Diversity & Inclusion Policy and Application Documents Rakuten’s corporate mission is to “contribute to society by creating value through innovation and entrepreneurship.” We foster a culture that provides equal opportunities to those who share this founding philosophy and take on the challenge to transform society, regardless of age, gender, nationality, or any other status. Diversity is one of Rakuten's core strategies and a driving force for innovation. Because of this, you are not required to submit any of the following information in order to apply for our job positions. - Gender - Age - Photo - Nationality - Information not related to business, such as ideological beliefs, family structure, etc. * For legal compliance, we may ask you about your work eligibility. See the details