Worked on enhancing the spring-projects/spring-ai repository by improving the flexibility and reliability of the ChatClientResponse.Builder API. Focused on supporting null context values, the developer introduced @Nullable annotations to clarify intent and prevent null-related runtime errors. They implemented unit tests to validate builder construction with null context, ensuring robust handling of edge cases and reducing the risk of regressions. Using Java and leveraging software development best practices, the work improved static analysis, integration scenarios, and overall maintainability. The changes contributed to clearer API contracts and expanded test coverage, reflecting a methodical approach to feature development and code quality.