Sentry is a powerful tool for capturing runtime errors and has recently been enhanced with features such as performance monitoring and release health. In the context of code refactoring, Sentry can be particularly useful in identifying deprecated code paths that are still in use. By leveraging Sentry's capabilities, developers can track down remaining call sites and fix them before removing the old code paths, ensuring a smooth transition during refactoring projects. The author of this case study used Sentry to update icons in their application, replacing deprecated forms with new React components, and successfully tracked down and fixed all remaining call sites using Sentry's event tracking capabilities.