1. A system for enabling application tasking in an application execution system from an external web application which is external to the application execution system, the system comprising: one or more processing devices; and one or more storage devices storing instructions that, when executed by the one or more processing devices, cause the one or more processing devices to: receive, a task from the external web application destined for a specific task queue for a specific internal web application which is hosted inside the application execution system; verify, using an authorization process, permission of the external web application to the specific task queue by checking information within a queue configuration file of the specific internal web application to determine whether the external web application has a sufficient privilege level to access and write to the specific internal web application's specific task queue; responsive to the verification, append, using a method in an external REST Task Queue API, the task to the specific task queue; and assign the task to a worker process in the specific internal web application such that the worker process: leases, using the method in the external REST Task Queue API, the task from the specific task queue; determines whether to process the task at a current time based on whether the internal web application is busy; modifies the task lease to zero seconds, if it is determined not to process the task at the current time, and releases, using the method in the external REST Task Queue API, the task to another worker process for processing; processes the task by the worker process if it is determined that the specific internal web application is not busy; and responsive to completing the task, removes, using the method in the external REST Task Queue API, the task from the specific task queue.