Worked on backend performance and reliability improvements across Shopify/rails and rubocop/rubocop repositories using Ruby. Delivered a schema search path optimization for Shopify/rails that prevents unnecessary queries when the schema_search value remains unchanged, reducing redundant work and improving runtime efficiency under load. In rubocop/rubocop, addressed a cache memoization issue in parallel processing by ensuring correct cache usage and consistent cache keys, which improved reliability and reduced duplicate analysis during parallel runs. Focused on bug fixing, caching, code refactoring, and parallel processing, with clear documentation and traceability for each change. Prioritized maintainability and scalability in all contributions over a two-month period.