Backend Java Engineer

Job Description: This role focuses on building and evolving backend microservices for large‑scale e‑commerce platforms. You will take ownership of core systems that support customer rewards, order delivery logic, and high‑volume transactions. Key Responsibilities: - Design, develop, and maintain backend microservices using Java (JDK11+) - Build scalable, high‑performance systems handling large volumes of traffic and data - Contribute new features and services that enhance customer value - Collaborate closely with platform and framework teams to improve overall engineering productivity - Promote a culture of quality, innovation, and customer‑focused development - Take strong ownership of the systems you build, from design through operation Requirements: - 5+ years of hands‑on experience with Java (JDK11 or above) - Experience with modern Java frameworks (e.g., Spring or micro‑frameworks) - Experience with both relational and NoSQL databases (e.g., Couchbase, CockroachDB, TiDB, or similar) - Practical experience with event‑driven architectures (Kafka, Confluent Kafka, Apache Pulsar, etc.) - Experience using containers and cloud platforms - Working knowledge of CI/CD pipelines and DevOps practices - Experience using source control systems, ideally Git Nice to have: - Experience working in Agile/Scrum development environments - Strong understanding of SDLC best practices, including code reviews and testing - Experience designing high‑availability architectures - Knowledge of APM tools and performance tuning - Familiarity with reactive programming and gRPC - Administration experience with NoSQL databases or message brokers Job Offer: - Exposure to large‑scale, high‑traffic e‑commerce systems - English‑speaking environment with no Japanese language requirement - Professional, collaborative engineering culture