Worked on the dotnet/runtime repository to address a critical issue in XML serialization involving value types implementing IXmlSerializable. Focused on correcting the boxing behavior in the XmlSerializer-generated IL, the developer implemented targeted changes to the serialization path using C# and IL generation techniques. This fix ensured that value types with parameterless constructors were properly boxed, preventing deserialization failures and avoiding InvalidProgramException during XML round-trips. The solution was validated with representative scenarios and committed to resolve issue #99613. Their work improved the reliability and robustness of XML serialization in .NET, leveraging expertise in C#, XML serialization, and IL generation.