A dataflow execution environment is provided with dynamic placement of cache operations and action execution ordering. An exemplary method comprises: obtaining a current cache placement plan for a dataflow comprised of multiple operations and a corresponding current cache gain estimate; selecting an action to execute from a plurality of remaining dataflow actions based on a predefined policy; executing one or more operations in a lineage of the selected action and estimating an error as a difference in an observed execution time and an estimated execution time given by a cost model; obtaining an alternative cache placement plan for the dataflow following the execution in conjunction with a predefined new plan determination criteria being satisfied and a corresponding alternative cache gain estimate; implementing the alternative cache placement plan in conjunction with a predefined new plan implementation criteria being satisfied; and selecting a next action to execute from a plurality of remaining actions in the dataflow based on a predefined policy.