45% Faster React Functional Components, NowJump to TL;DR at the end to see one easy change you can apply to your React code to get a free speedup. For more details, read on. I work on Missive, a team email/chat client built with React. It uses a multi-column layout to display conversations. On ⬆︎️⬇ key presses, the app navigates to a new conversation. It needs to do so in as few milliseconds as possible to avoid any user-perceivable delay.
