Political polarization. Climate change. Racial reckoning. Income inequality. A global pandemic. Since 2020, all five of these immense challenges have emerged or deepened, commanding our attention and prompting major societal and cultural shifts. In this special series produced in partnership by The Pew Charitable Trusts and the Stanford Social Innovation Review, we talk with leaders from across the social sector. They take us behind the scenes, sharing case studies of innovation and resilience.