Cleerly Labs is a complex, physician-facing web experience showing multiple, coordinated images simultaneously with large amounts of overlay statistical data on many scrollable image slices. This experience is meant to be smooth and easy to use for Cardiologists and other physician personas but keeping it responsive and delightful has proven challenging given the large amount of visual data being shown. We'll talk through how we've solved slow rendering and laggy user interaction experience in our web UI in this talk.