Implemented flexible module builder allowed import and analysis of any needed data with Spring MVC.

Boosted platform performance by 50% through successful transformation into multithreaded scalable microservices architecture using Spring Boot, Eureka, Zuul, PostgreSQL and MongoDB.

Reduced operating costs by 25% by implementing data import in batches, leading to optimized memory usage thus attaining same performance from smaller instances.

Improved user experience by designing and implementing intelligent data skipping and caching techniques reducing average user wait time from 3s to under 200ms during report fetching.

Developed a robust security library using OWASP, resulting in a 95% reduction in vulnerabilities and successful external penetration tests.

Achieved 90% code coverage through rigorous unit and integration testing using SonarQube, JUnit and Mockito.

Mentored and guided junior engineers, fostering a culture of continuous learning and growth.

Streamlined the architecture by replacing Camel with Spring MVC, leading to a 20% reduction in config files.

Slashed costs by transitioning from OracleDB to PostgreSQL, resulting in a 60% decrease in instance expenses.

Implemented data partitioning and materialized views, reducing data size and query time by 3 times.

Introduced partitioning and multi-threaded data saving, halving import time on the same instance size.

Ensured software quality by covering the existing API with tests using SonarQube, JUnit, Mockito, Powermock and introducing Test-Driven Development TDD, reducing regression bugs by 20%.

Developed web data scraping scripts using Java and XML.

Parsed and extracted deeply nested and archived files using Apache POI.

Conducted thorough testing with Selenium, achieving approximately 70% coverage.