Java Developer (Mid-Level)
Summary
Mid-level Java developer building backend services with Spring Boot, optimizing high-concurrency systems, and tuning MySQL/PostgreSQL databases.
We are looking for a mid-level Java Developer with around 3 years of experience to join our development team. This is a hands-on coding role with no people management responsibilities. You will focus on building robust, high-performance backend services, collaborating closely with product managers, DBAs, and QA engineers.
Key Responsibilities
Design, develop, and maintain backend modules using Java and the Spring ecosystem.
Write clean, efficient, and well-tested code with a strong emphasis on performance and scalability.
Optimize multi-threaded processing and high-concurrency logic to ensure system stability.
Collaborate with the DBA team on SQL tuning, indexing strategies, and database access optimization (MySQL/PostgreSQL).
Participate in code reviews, technical documentation, and agile ceremonies (Scrum/Kanban).
Troubleshoot production issues and deliver timely bug fixes.
Required Qualifications
Bachelor’s degree in Computer Science, Software Engineering, or a related field.
3+ years of professional Java development experience.
Skilled in database design and SQL optimization, familiar with mainstream database operation and performance tuning methods.
Strong hands-on experience with Spring Boot or Spring Cloud or other mainstream Java frameworks; practical experience in multi-threaded programming and high-performance system tuning.
Strong logical thinking and problem-solving skills, capable of parsing complex business requirements and delivering feasible technical solutions.
Japanese language skills – not mandatory, but highly appreciated (willingness to learn technical Japanese is also a plus).