Sentry’s Frontend Tests: Migrating from Enzyme to React Testing Library` is a story of how Sentry, a company that practices continuous delivery and automates testing for its large React codebase, successfully migrated its frontend tests from Enzyme to React Testing Library (RTL). The migration took over a year and four months, involved contributions from 17 engineers, and spanned 803 test suites and 4,937 tests. The team evaluated the benefits of using RTL, including improved accessibility, better performance, and enhanced testing capabilities. They also encountered challenges such as poor performance when using certain queries and missing ARIA roles on elements. Despite these obstacles, the team persevered and eventually completed the migration with 644 files converted to use RTL at the time of completion. The successful migration has improved Sentry's frontend tests and made them more confident in their testing process.