A system trace can tell you when a thread ran, which CPU core it ran on, and which FrameTimeline frame missed its deadline. With Binder/ftrace/sched evidence enabled, it can also reconstruct Binder calls and clues about waiting. But it does not know which frame ID a player is decoding, which scene a game engine is loading, or how long an application task has spent in a queue.

Track Events can record decoding, texture uploads, queue depth, and cross-thread task IDs. Put them in the same window as the system tracks to find a candidate application phase, then use RenderThread, GPU, and FrameTimeline evidence to check whether it affected a visible frame.

The article follows the practical integration order: decide whether instrumentation is needed and at which layer, define an application-phase dictionary and backend, then build the minimal integration, category controls, combined system capture, and cross-thread flows. Finally, control write volume and define the app-side field tracing protocol.