Quang Dao contributed to the a16z/jolt and leanprover-community/batteries repositories, focusing on correctness and reliability in systems programming and formal verification. For a16z/jolt, Quang improved signed remainder validation by refactoring Rust code to handle edge cases in 32-bit and 64-bit scenarios, expanding test coverage and aligning range calculations to prevent misalignment issues. In leanprover-community/batteries, Quang extended Lean’s Batteries library by introducing lawful lifting for monad transformers, ensuring that lifting operations preserved key properties when composing monads. This work demonstrated depth in type theory, functional programming, and testing, resulting in more robust and maintainable codebases.