A system can stream content items and ad items to a user interface of a client-side application (such as a web browser) without refreshing the user interface and by requesting such items from a local cache and/or a remote cache associated with the client-side application or the user interface. The remote cache can operate much like a local cache for the client-side application or the user interface. Items can be streamed to a user interface without refreshing the user interface and by requesting such items from a remote cache dedicated to caching the items that can be presented by the user interface. Because the tracking of such items and the tracking of the interactions with such items creates such large amounts of data, communicating the tracked data may be impracticable without use of a system that can effectively compress associated instrumentation data.