1. A personalization system to generate personalized results for an online user, the personalization system comprising: memory; and one or more processors communicatively coupled to the memory, the one or more processors being configured to cause the system to perform operations comprising: receive a plurality of user events, each user event of the plurality of user events including one or more user events selected from a group of user events consisting of: a transactional event and a behavioral event associated with the online user; receive a personalization request for a session from a requesting system, the personalization request including an identifier of the user, a query fragment, and an indication of a query type of personalization that is to be performed, the query fragment having been received via a graphical user interface; identify a plurality of intermediate results based on the query fragment, each intermediate result of the plurality of intermediate results representing a possible outcome that may be presented by the requesting system to the online user, wherein the plurality of intermediate results include a first term that was previously searched by the user and a second term that was previously searched by the user, wherein the first term and the second term are identified by accessing an electronic data storage that includes an electronic record of terms that were previously searched by the user; compute a score for each intermediate result of the plurality of intermediate results based at least in part on the plurality of user events, thereby generating a plurality of scores, wherein a first score is computed for the first term based on a first search date of the first term, wherein a second score is computed for the second term based on a second search date of the second term, wherein the first search date is within the session and the second search date is outside the session; generate a personalization response that includes the first term and the second term, wherein the first term is prioritized over the second term based on the first search date being with the session; and send the personalization response to the requesting system for use in personalizing an online experience of the online user.