Naoto Hasegawa focused on stabilizing the OpenAI HTTP client integration within the UKGovernmentBEIS/inspect_ai repository, addressing reliability issues related to HTTP proxy support. He refactored the OpenAIAsyncHttpxClient to remove a custom transport layer, opting instead for OpenAI’s default settings to ensure compatibility with standard proxy configurations. Using Python, he implemented automated testing to verify that the client correctly respects HTTP proxy settings, which reduced proxy-related failures and support requests. His work emphasized backend development and API integration, resulting in a more robust and maintainable codebase. The depth of his contribution lay in targeted, test-driven improvements to system reliability.