Pope Leo XIV has declared a 15-year-old computer whiz the Catholic Church’s first millennial saint. Carlo Acutis, who died in 2006, was canonized during an open-air Mass in St. Peter’s Square on Sunday. Tens of thousands attended, including many millennials and families. Acutis, known as “God’s influencer,” used technology to spread his faith. The Vatican said 36 cardinals, 270 bishops, and 212 priests participated in the Mass. The ceremony also canonized Pier Giorgio Frassati, another young Italian figure. Both ceremonies were postponed earlier this year following Pope Francis’ death in April.