In many youth programs, teenagers learn social, emotional, and strategic thinking skills through dealing with the challenges of meaningful projects (e.g., planning an event, creating a video, putting on a play). In 25 years of research with high-quality project-based programs, we found that youth develop skills through their active, invested engagement with project challenges, such as trying to reach a difficult goal, grappling with real-world obstacles, and dealing with interpersonal and emotional challenges. Youth learn from processes of planning and adjusting plans, solving problems, and evaluating how steps they took did or did not succeed in moving their work forward. The experienced program staff in these programs play important roles in supporting youth’s learning from challenges. They give youth ownership over making decisions and dealing with problems that arise in their projects. When needed, staff use their knowledge to provide judicious input on youth’s work. This can include encouraging youth to explore possible scenarios in their work, redirecting youth when a plan is not likely to succeed, and helping youth see obstacles as “challenges” they can solve or work around. Staff provide honest and straightforward feedback on youth’s work that helps them fix problems, understand challenges, and learn from experiences.