A computing resource service provider may provide computing resources for execution of a program on behalf of a customer. The program's resource requirements may grow over time and horizontal scaling of the programs execution may be a laborious task as the portion of the program's the in-memory state may not be replicated. The program may include a set of modules which may be split and distributed to one or more computer systems of the service provider for execution. A factoring plan may be used to determine a set of partitions, where each partitions contains a subset of the modules of the program. Performance data associated with the one or more computer systems executing the partitions may be used to determine the factoring plan.