Feature rich Compose screens often produce frozen frames—any frame over 700 ms—when multiple heavy UI sections are composed in a single pass. Users are forced to wait for the entire screen to finish composing before seeing anything meaningful, creating slow and unresponsive first-load moments.

This talk presents Phased Compose, a phased rendering technique that splits a large composition into deterministic steps. Instead of generating one long frozen frame, each major section renders in its own phase, allowing meaningful content to appear immediately while remaining parts compose progressively. This approach reduced frozen frames by over 30% on complex screens—without delays, timers.

I will explain why existing APIs like PausableComposition and lazy layouts don’t solve first-frame jank, and how Phased Compose provides a general, predictable solution. Attendees will learn how to apply phased rendering to ship smoother startup experiences and eliminate long UI stalls in real apps.