Abstract: Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for dynamic user data filtering. In some implementations, a method includes determining one or more values using data representing a sequence of one or more types of interactions between a user and content; using the one or more values to determine whether to include each interaction of the one or more types of interactions in the sequence within a reduced user data set; generating the reduced user data set by removing one or more interactions from the sequence based on determining not to include the one or more interactions using the one or more values; and providing the reduced user data set to a processing server.