Ivan M.

Senior Java Software Engineer with 7+ years of experience building, maintaining, and troubleshooting production backend and database systems. My Certifications: - Oracle Certified Associate Java Programmer - 75% - Oracle Certified Professional Java Programmer - 80% - VMware Spring Professional Certification Exam - 85% - Oracle Database 19c Administration Level 1 - 65% - MySQL 8.0 Database Developer - 85% I specialize in Java, Spring Boot, and relational databases. I’m particularly interested in focused technical assignments—problems that need experienced investigation and a reliable solution. I can help with: • Debugging Java and Spring Boot applications • REST API development, troubleshooting, and third-party integrations • Java, Spring Boot, Maven, and Gradle upgrades • Hibernate, JPA, JDBC, and persistence-layer problems • SQL debugging and query performance optimization • Database design, schema changes, indexing, and data migrations • Transactions, locking, concurrency, and data-consistency issues • Oracle Database, PostgreSQL, MySQL, and Microsoft SQL Server • Spring Security, authentication, and authorization • Project Reactor, Spring WebFlux, and reactive applications • Kafka integrations and event-driven systems • Testing with JUnit and Mockito • Docker, Linux, Jenkins, and deployment troubleshooting • Code reviews, refactoring, and focused backend features I use modern AI-assisted engineering tools extensively to analyze new codebases, investigate problems, evaluate possible solutions, create targeted tests, and improve documentation. I review and verify the results myself and remain fully responsible for every delivered change.