1. A method comprising: receiving, at a processor, a plurality of content items obtained from content streams of different content types to be forwarded to at least one user; scoring, by the processor, at least a subset of the plurality of content items based on a user model; adding, by the processor, at least a subset of the scored content items to respective lists of unseen content items for the user based at least on respective scores; receiving, by the processor, a request from the user for relevant unseen content items; rescoring, by the processor, the content items added to the lists of unseen content items based on a current context of the user upon receiving the user request; selecting, by the processor, top scoring content items from the first subset of content items; and forwarding, by the processor, the selected top scoring content items to the user in response to the user request for the relevant items.