AWS Lambda allows any Node.js app to be run at scale in a massively parallel environment with no up-front costs or planning. This session shows how to use Lambda to build dynamic analytic data flows that can be tuned as they execute, based on initial results, to provide real-time output streamed to web clients. This process enables a cost-effective and responsive user experience for ad hoc big data jobs and lets developers focus on how data is consumed and presented, instead of how it is obtained.