DevOps Engineer - Contractor

Responsibilities: 1. Design and develop backend architecture for business systems, ensuring high availability, high performance, and scalability. 2. Perform service governance and performance tuning in high-concurrency scenarios to continuously improve system stability, throughput, and response efficiency. 3. Develop core services and business modules, including user systems, authentication, authorization, and open API capabilities. 4. Participate in microservices architecture design and implementation, promoting system modularization, service-orientation, and engineering excellence. 5. Troubleshoot production issues, analyze performance, and resolve complex technical problems. 6. Collaborate with product, frontend, QA, and cross-functional teams to ensure high-quality delivery of requirements. 7. Continuously optimize development processes, code quality, and technical solutions to improve maintainability and R&D efficiency.   Qualifications: 1. Bachelor's degree or above in Computer Science or a related field. 2. 3-5+ years of Java backend development experience with a solid technical foundation. Outstanding fresh graduates may also be considered. 3. Proficiency in Java core technologies, with a deep understanding of JVM, concurrency programming, collection frameworks, I/O, and network communication. 4. Familiarity with mainstream frameworks like Spring Boot and Spring Cloud, with experience in microservices development and governance. 5. Experience in developing high-performance, high-concurrency systems, with familiarity in caching, asynchronous processing, rate limiting, circuit breaking, and thread pools. 6. Proficiency in common middleware such as MySQL, Redis, Kafka, and Elasticsearch, with an understanding of their use cases and performance optimization methods. 7. Understanding of common distributed system issues and solutions, including idempotency, consistency, distributed locks, transaction processing, and service fault tolerance. 8. Strong analytical and problem-solving skills, capable of independently troubleshooting production issues and resolving complex problems. 9. Familiarity with authentication and authorization mechanisms, with experience designing and developing with OAuth2, JWT, SSO, RBAC, and Session. 10. Experience with Kubernetes, including containerized deployment, service orchestration, auto-scaling, and configuration management. 11. Experience with AWS cloud services is a plus. 12. Strong coding standards, documentation skills, and teamwork abilities.