After Avi Schiffmann, 19, attended a February demonstration protesting Russia’s invasion of Ukraine, he realized he could do more to support refugees. With the help of his Harvard classmate Marco Burstein, 18, he built Ukraine Take Shelter, a site where people fleeing war can connect with hosts offering spaces to stay. The site quickly took off, and more than 10,000 Ukranians found sanctuary through it in the first month. Now Schiffmann would like to expand the site, adding things like transportation and jobs. He also hopes to inspire other young people to learn to code and use those skills to help others. “The internet is a very untapped tool for humanitarian crises,” he says. “I think it’s supercool to see these families that were able to use this site smiling on a beach. . . . You have no idea what the butterfly effects of something like this could really be.”