Abstract: Technologies for unseen notification handling are described. Embodiments select an initial set of notifications, provide the selected initial set of notifications to a client device, store seen notifications in a first data store, maintain sent but unseen notifications in a second data store that is an in-memory online data store, retrieve a set of the sent but unseen notifications from the second data store, create a list of unseen notifications by combining the retrieved set of sent but unseen notifications with a set of unsent and unseen notifications, generate a set of relevance scores for the list of unseen notifications, create a new version of the list of unseen notifications based on the new set of relevance scores, and provide the new version of the list of the unseen notifications to the client device.

Abstract: Disclosed in some examples are methods, systems, and machine readable mediums which allow for fast and efficient advertisement selection using search indices. Selection criteria of the advertisement campaigns are converted into documents using a conversion schema. The documents are then indexed to create an advertising campaign index. Member profile data is then converted into a member search query using the conversion schema. The member search query is then issued to a search engine which uses the advertising campaign index to find matching campaigns.