1. At a computer system, the computer system including a processor and system memory, a method for presenting diagnostic data for an application, the method comprising: displaying, at a visualization user interface that represents a timeline of execution of the application, a first swim lane user interface element along the timeline, the first swim lane including one or more diagnostic visualizations emitted during execution of the application, the one or more diagnostic visualizations comprising one or more spans that each represent a duration along the timeline of performance of an abstract objective of the application using one or more hardware components during execution of the application, the one or more diagnostic visualizations including a particular span associated with particular one or more hardware components; displaying, at the visualization interface, a second swim lane user interface element along the timeline that corresponds to the first swim lane and that is parallel to the first swim lane, the second swim lane including diagnostic data indicating one or more instants in time along the timeline of occurrence one or more events at the one or more hardware components during execution of the application, the diagnostic data including particular one or more events that occurred at the particular one or more hardware components during execution of the application; and within the visualization interface, visually correlating the displayed one or more diagnostic visualizations with the displayed diagnostic data, including using a same color for the particular span and for the particular one or more events that occurred at the particular one or more hardware components associated with the particular span during execution of the application.