Worked across excalidraw/excalidraw, actualbudget/actual, and spree/spree repositories to enhance reliability and user experience by addressing three targeted bugs. Focused on JavaScript, Ruby, and React, the work included correcting shape roundness handling in Excalidraw to ensure accurate rendering when converting between shapes, and refining batch selection logic in Actual to exclude hidden reconciled transactions from user actions. In Spree, stabilized end-to-end tests for the VariantsController by accommodating unordered, capped results, improving test determinism. Emphasized test-driven development and end-to-end testing to deliver safer data actions, more predictable UI behavior, and increased confidence in release quality across projects.