Boston Mayor Thomas Menino is an urban legend - the closest thing the East Coast has to Chicago Mayor Richard Daley. So when Menino stood for a fifth term last year, most observers saw his re-election as a foregone conclusion. Instead, the mayor attracted a passel of charismatic challengers who claimed that the old-school mayor had exercised power for long enough, and that "The Hub" needed someone who was younger and, well, hipper.

Come primary and election day, Menino handily dispatched his challengers. But the recent appointment of 33-year-old Mitchell Weiss as his chief of staff shows that the mayor took at least some of their message to heart.

Weiss is a Chicago native who's drawn more to the intricacies of behavioral economics than the fine-grained tribal distinctions that have long characterized Boston politics. For the past four years, he's worked as the executive director of the Tobin Project, a Cambridge-based think tank devoted to bringing academic insights to public policy problems. But in his new role, Weiss will be taking on a very South Boston project: shaping Southie's 1,000-acre Seaport District into a true 24/7 mixed-use neighborhood.