Claire Walsh, J-PAL leader offering career tips; Mushtaq Khan, political-economy economist; Leah Utyasheva, researcher on pesticide bans; James Snowden, funder on moral tradeoffs; Alexander Berger, cause-prioritization strategist; Varsha Venugopal, community immunisation innovator; James Tibenderana, malaria and gene-drive expert; Lucia Coulter, lead-paint campaigner; Hannah Ritchie, agricultural data scientist; Rachel Glennerster, RCT specialist; Sarah Eustis-Guthrie, evaluator; Dean Spears, neonatal nutrition researcher; Karen Levy, governance consultant. They discuss pesticide bans, gene drives for malaria, boosting African farm productivity, lead-paint regulation, village influencers for vaccination, and how institutions and incentives shape what scales.