1. A system for processing a set of computer programs instances, with inter-task communications (ITC) performance isolation among the set of program instances, the system comprising: a number of processing stages, at least one of which comprises multiple processing cores, with, for at least one of the cores, one of the program instances assigned for execution for a period of time; and a group of multiplexers connecting ITC data to a given stage among the processing stages, wherein at least one of the multiplexers is specific to one given program instance among said set, wherein the system is configured to host each task of the given program instance at different one of the processing stages, while supporting copies of software code of same given task located at more than one of the processing stages.