Over a two-month period, xstefank122 contributed targeted engineering work to the quarkusio/quarkus-quickstarts and langchain4j/langchain4j repositories. In quarkus-quickstarts, he improved the reliability of REST Client Quickstart tests by aligning them with the correct extension and native SSL guide, reducing CI flakiness and streamlining onboarding for new contributors. For langchain4j, he implemented a configurable limit for sequential tool invocations in AiServices, updating both the core logic and unit tests to enforce safer resource usage. His work demonstrated practical application of Java, REST API design, and unit testing, addressing specific pain points with focused, maintainable solutions.