The theme of Development Dialogue 2015 was ‘Scaling by Proving’, emphasizing the path to truly scalable developmental impact. By ‘Failing Small, Failing Early, Failing Fast’, organizations can test their hypotheses and new approaches at a small scale, rapidly pivot ideas, learn from mistakes and make quicker midcourse corrections early on in their implementation. Panelists discussed how during this early ‘Proof of Concept’ phase organizations can also create networks and coalitions, test the relationships and enact processes that lead to rapid growth. The Dialogue showcased several examples of organizations that tested alternatives at early stages, learnt from their successes and mistakes, and then moved ahead to scale their implementation in different dimensions.