[Listen Notes] Upgraded React from 17 to 19

The Listen Notes website frontend is built with React, and we’ve just completed a major upgrade from React 17 to React 19.

React 17 was released in 2020—nearly six years ago. As a rule of thumb, we try not to leave critical infrastructure, libraries, or frameworks on outdated versions for too long. The longer an upgrade is postponed, the more difficult it can become as technical debt compounds. Staying current (but not the newest version!) also helps us benefit from the latest security patches, performance improvements, and new features.

The upgrade went smoothly. We completed extensive end-to-end testing across all user-facing features on the website.

Hopefully, the next React upgrade won’t have to wait another six years. :)