Parth Kothari enhanced backend robustness and reusability across the googleapis/java-genai and google/adk-java repositories during May 2025. He made the HttpApiClient base API public in java-genai, clarifying its intended use with an @InternalApi annotation to prevent misuse. In adk-java, Parth refactored the Vertex AI runner, introducing session encoding and decoding utilities, a default constructor, and improved error handling for session state and event parsing, all in Java. He also implemented stricter agent configuration constraints through targeted unit tests, ensuring proper agent setup. Parth’s work focused on API development, integration, and agent development, emphasizing maintainability and runtime reliability.