1. A method for using functionality from a second application based on input from a first application, comprising: receiving input at a frontend, the input comprising at least a trigger action, wherein the frontend comprises a user interface of the first application; transmitting the input from the frontend to a controller; mapping, at the controller, the input to an action script comprising a set of commands corresponding to the input, the action script being executable at a backend, wherein the backend comprises a user interface of the second application; executing, at the backend, at least one action script based on the mapping at the controller; and determining, by applying a set of ambistateful criteria at the controller, whether to place the backend under stateless control or stateful control, upon completion of execution of the at least one action script.