This presentation will provide the attendee with an introduction to data processing in GeoServer by means of WPS, rendering transformations and SQL views, describing real applications and how these facilities were used in them. We'll start with the basic WPS capabilities, showing how to build processing request based on existing processes and how to build new processes leveraging scripting languages, and introducing unique GeoServer integration features, showing how processing can seamlessly integrate directly in the GeoServer data sources and complement existing services. Moreover, we will show how to integrate on the fly processing in WMS requests, achieving high performance data displays without having to pre-process the data in advance, and allowing the caller to interactively choose processing parameters. While the above shows how to make GeoServer perform the work, the processing abilities of spatial databases should not be forgotten, so we will show how certain classes of processing can be achieved directly in the database. At the end the attendee will be able to easily issue WPS requests both for Vectors and Rasters to GeoServer through the WPS Demo Builder, enrich SLDs with on-the-fly rendering transformations.