Formerly known for tea parties, marathons, and raucous local politics, Boston has become a center for innovators providing new ways of shopping. A trip to the store has been replaced by a trip to the front door thanks to e-commerce firms like Demandware, CarGurus, Chewy, Wayfair, and M.Gemi. These hot shops are heavy users of technology solution providers focused on e-commerce, martech, and supply chain.