An observation system includes mechanisms for efficiently tracking the state of source components, which include functions, arguments, or values, etc. In one implementation, an observing component requests that a source component processes a request. The observation system then identifies all possible components in a dependency chain for the request, and all such components that are configured for change notifications. A dependency registry stores a representation of each identified component that is configured for change notifications. Any time any component configured for change notifications changes, including indirectly related components, the observing component can be immediately notified of the change, without having to reprocess the entire set of component dependencies.