The growth of your protocol ecosystem is rooted in the ease at which developers can build applications using your tools. How do you create intuitive, powerful developer experiences to encourage people to build a vibrant application ecosystem? We share the behind the scenes of what really goes into powering marquee developer communities. In this talk, we cover the design and implementation of custom APIs for some of the most popular applications: CheezeWizards by CryptoKitties, Kyber, and more.