Logan Circle; 110 employees
Whether you’re pinning a vacation spot on Pinterest or finding a coffee shop on Foursquare, you’re seeing the work of this five-year-old start-up. In June, the open-source mapping-data company further put itself on the, um, tech map when it announced $52.5 million in venture capital and a partnership with Mapquest. Three dozen mostly millennial employees work at the DC headquarters (there are also offices in Peru, India, and California) and say they’re excited by the firm’s success—it has almost tripled in size in 18 months—and by the interesting work. (Free Peregrine coffee helps keep up the energy, too.) The team gathers for free lunches on Mondays to kick off the week; a beer-and-wine fridge and Jenga nights help them kick back.
Perk: This “green” office composts food waste and runs on renewable energy.