Oki F.Private profile: Upwork shows its earnings only to signed-in members, so we check it every few weeks, not daily. MRR here is a rough estimate (Upwork's six-month earnings ÷ months active). Last read Nov 5, 2026.

I’m a Java / Spring Boot Backend Developer specializing in REST APIs, third-party integrations, and production backend systems. I have experience building, maintaining, and improving backend applications using Java, Spring Boot, PostgreSQL, JPA/Hibernate, Redis, and Docker. I also work with Vue.js when frontend development is required. I can help you with: - Building REST APIs and backend services with Java & Spring Boot - Integrating third-party APIs and external platforms - Implementing OAuth2 and authentication integrations - Designing and optimizing PostgreSQL databases and SQL queries - Debugging production issues and fixing existing applications - Maintaining and modernizing existing Java/Spring codebases - Developing Vue.js frontend features when needed Tech stack: Java, Spring Boot, Spring Framework, JPA/Hibernate, PostgreSQL, SQL, REST APIs, OAuth2, Redis, Docker, Maven, Git, JUnit, Vue.js, JavaScript/Typescript. I’m comfortable working with existing production codebases, understanding established architecture and patterns, debugging complex issues, and implementing changes without unnecessarily rewriting working systems. I focus on clean, maintainable code, practical solutions, and clear communication. Whether you need a new Spring Boot API, third-party integration, bug fix, database optimization, or help maintaining an existing Java application, I’d be happy to help.