A Library of Congress/CIC researcher, Lagos is basically in love with information. He coded the program that eventually became the Librarian, who characterizes his creator as someone who "'devoted himself to the common problem of sifting through vast amounts of irrelevant detail in order to find significant gems of information'" (13.55). That's an exercise in patience and love if we've ever seen one.
While this all sounds very noble, though, Lagos earns everyone's scorn for going about his information-quest as a gargoyle, a.k.a. a "human surveillance" device who walks around wearing his computer and recording everything around him (15.15). He's so wrapped up in sifting through information when he and Hiro meet that Hiro ends up really irritated that Lagos—despite obviously being really intelligent—can't carry on a conversation like a normal human being.
Plus, all the fancy tech in the world doesn't save Lagos when Raven gets ticked off at him, so Lagos winds up dying in a puddle of blood. At least his information lives on, in the CIC and in the form of the Librarian.