Daily Prebuilt, a ready-to-use embeddable video chat solution offered by Daily, aims to provide reliable and easy-to-use video calls in the shortest developer time possible. To achieve this, Daily has redesigned Daily Prebuilt to incorporate helpful customer feedback, resulting in improved UX. The redesign also revealed several performance issues, particularly on mobile devices and Safari browsers for WebRTC. To address these issues, Daily has developed a series of performance optimizations, including batching daily-js events, manual track subscriptions, virtualized lists, pagination, memoization, and avoiding unnecessary removal and addition of videos. These optimizations can help improve the performance of custom video chat apps built with Daily's call object or Prebuilt solutions.