1. An apparatus, comprising: a processor; and a non-transitory computer-readable storage medium having instructions stored thereupon which are executable by the processor and which, when executed, cause the processor to: receive user-specified data defining a software release pipeline, the software release pipeline comprising one or more stages, the one or more stages comprising one or more actions, the one or more actions comprising one or more internal actions and one or more external actions, wherein the one or more internal actions are to be performed with one or more internal network services within a service provider network, and wherein the one or more external actions are to be performed with one or more external network services that are implemented on computing resources that are external to the service provider network; determine whether an action of the one or more actions to be performed during execution of the software release pipeline comprises an internal action or an external action; in response to determining that the action to be performed comprises an internal action, execute an internal job worker associated with the internal action, the internal job worker configured to utilize one or more internal network services within the service provider network to perform the internal action; and in response to determining that the action to be performed comprises an external action, execute an external job worker associated with the external action, the external job worker configured to utilize one or more external network services that are external to the service provider network to perform the external action.