Systems, methods, and articles of manufacture are disclosed for processing element (PE) deployment placement in a streaming data system. In particular, PEs of a stream computing application are grouped across compute nodes in a dynamic manner that improves over manually specified groupings of PEs on particular compute nodes. A stream manager deploys PEs according to rules in deployment instructions specifying whether to collocate PEs on a single compute node and/or ex-collocate PEs across compute nodes based on dynamically-determined information relating to the PEs themselves, compute nodes on which PEs are to run, and/or the streams runtime. For example, the stream manager may profile code and deploy PEs on compute nodes based on such profiling, deploy PEs together on compute nodes meeting predefined system characteristics or streams runtime conditions or metrics, and/or deploy PEs on a compute node within a predefined proximity of an external source.