Worked on enhancing the stability and interoperability of the HTTP client layer within the symfony/symfony repository, focusing on backend development and API integration using PHP. Addressed a nuanced issue in the HttplugClient and Psr18Client components by refining how empty request bodies are handled, ensuring that Content-Length and Transfer-Encoding headers are omitted when the body size is zero. This adjustment reduced the risk of malformed requests and improved compatibility with various HTTP clients. Demonstrated careful attention to HTTP protocol details, resulting in more reliable outbound requests across different environments and external services, and contributed to overall robustness in HTTP client interactions.