A computer-implemented method can include executing a first application in stateful manner, wherein the first application executes continuously while receiving a sequence of a plurality of inputs from a user; and, in response to each of at least some of the plurality of inputs at the first application, executing a second application in a stateless manner by an execution controller, wherein the stateless execution can include the execution controller instructing the second application to execute an ordered stack of action scripts, the second application initiating and executing the ordered stack of action scripts, and the second application terminating upon completion of the executing of the ordered stack of action scripts.