The development boom along the Hudson waterfront has put Jersey City in rare company, making it one of only 18 U.S. cities with at least five skyscrapers. That’s according to a recent study of high-rise architecture by Yardi Matrix, a commercial real estate research and data platform, which also found that Jersey City currently has the fourth-tallest building under construction in the U.S. That project, 99 Hudson, is a 79-story luxury condominium tower that is slated to rise 889 feet when it opens next year.