Qiuhao Li worked on the Babylon repository, focusing on backend development with Go to enhance the reliability of proposal processing at epoch boundaries. He addressed a runtime panic in the checkpointing module by replacing an unsafe type assertion with a safe type check for injected checkpoint transactions, ensuring that invalid transactions are rejected gracefully. To validate this fix, he implemented regression tests that confirm the system no longer panics and correctly rejects incorrect message types. This work improved the stability and security of the ABCI++ proposal validation path, aligning with security advisories and maintaining robust test coverage without impacting performance.