Santiago Gil Rodriguez focused on stabilizing the recurly-js checkout flow by updating test fixtures to match recent Checkout Session API changes. Working primarily in JavaScript, he addressed a critical maintenance need by eliminating test data drift, which had been causing unreliable test outcomes and CI instability. His approach emphasized fixture management and rigorous testing practices, ensuring that automated tests remained consistent and maintainable as the API evolved. By aligning test data with internal logic in the recurly/recurly-js repository, Santiago improved code hygiene and prepared the codebase for future API migrations, ultimately supporting more predictable releases and faster development feedback cycles.