Worked on backend and agent development across the googleapis/java-genai and google/adk-java repositories, focusing on API development and integration using Java. Enabled broader reuse by making the HttpApiClient base API public in java-genai, while clarifying its intended usage with internal annotations to prevent misuse. In adk-java, refactored the Vertex AI runner and introduced session utilities for encoding and decoding, improving error handling and reliability of session state management. Added targeted unit tests to enforce agent configuration constraints, ensuring proper setup and reducing runtime incidents. The work emphasized robust integration, maintainable code, and comprehensive unit testing to support scalable backend systems.