Slides of QCon London 2016 talk. How stream processing is used within the Uber's Marketplace system to solve a wide range problems, including but not limited to realtime indexing and querying of geospatial time series, aggregation and computing of streaming data, and extracting patterns from data streams. In addition, it will touch upon various TimeSeries analysis and predictions. The underlying systems utilize many open source technologies such as Apache Kafka, Samza and Spark streaming.