Join OPPO US Research Center’s core team to develop and optimize backend services for high-traffic products (App Store, Global Search, Game Center). You’ll build scalable, reliable systems that serve millions of daily users. Key Responsibilities: Design and implement backend services for recommendation and search with a focus on low latency and high availability. Implement multi-level caching and optimize data access patterns. Build, monitor and tune data pipelines and indices using Redis, Elasticsearch, and Kafka. Develop production-quality Java services using Spring / Spring Boot and collaborate on deployments and incident response. Work cross-functionally with MLE, product, SRE, and data teams to deliver features and improvements. Requirements Minimum Qualifications: BS or MS in Computer Science or a related field. 4+ years building backend systems in Java (Spring / Spring Boot). Solid knowledge of multithreading, caching strategies, and distributed systems. Hands-on with Redis, Elasticsearch, and Kafka. Good communication, problem solving and teamwork skills. Preferred Qualifications: Experience in recommender or search system backends. Experience operating high-traffic, high-concurrency services. Benefits OPPO is proud to be an equal opportunity workplace. We are committed to equal employment opportunity regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity or Veteran status. We also consider qualified applicants regardless of criminal histories, consistent with legal requirements. The US base salary range for this contractor position is 60-120/hour. Our salary ranges are determined by role, level, and location.