Demand-driven architectures permit clients to pull arbitrary information on demand. Companies like Facebook and Netflix are transitioning to demand-driven architectures because they better accommodate diversifying and ever-changing clients. Conventional designs often rigidly front load decisions leading to brittle, inefficient systems with endless corridors of incidental complexity. Architectures that instead permit clients to request information on demand, such as Relay and Falcor/JSONGraph, give developers a way out. Database solutions like Datomic permit running demand driven queries directly without the arbitrary limitations of document or key-value stores. By embracing demand driven architectures we can more flexibly accommodate the rapidly transforming needs of today's clients (web, native, data api consumers) while paving the way for the unforeseen clients of the future.