Worked on the Helicone/helicone repository to refactor route definitions and data models related to experiments, datasets, and evaluators, focusing on improving codebase cleanliness and maintainability. The approach emphasized preserving existing core functionality while restructuring backend architecture for clearer data contracts and easier future feature development. Utilized TypeScript and Node.js, leveraging Tsoa for API design to ensure scalable and organized routing. No critical production incidents occurred during this period, and incremental performance improvements, such as batching reads, were introduced. The work laid a solid foundation for future modernization efforts, supporting maintainable growth and streamlined backend development processes within the project.