A. Leo Barreiro developed foundational C++ language support and tooling for the ThePrimeagen/99 repository, enabling rapid prototyping and reliable code generation for C++ modules. Barreiro implemented language entry points, logging, and tree-sitter grammars, integrating a basic CMake build system with example files to demonstrate module usage. The work included refining code parsing for lambdas and functions, improving import handling, and adding comprehensive tests to ensure build reproducibility and maintain code quality. Leveraging C++, Lua, and tree-sitter, Barreiro’s contributions provided robust infrastructure for module development, focusing on technical depth and maintainability while addressing core business and engineering needs.