A framework can provide describe definitions for use cases. The framework can comprise a controller layer, a wrapper layer, and a function layer. The controller layer can be configured to receive describe requests and return describe results. The wrapper layer can be configured to call describe methods of functions that implement the use cases. The function layer can comprise functions that implement the use cases. A function execution request can be received, a customized function execution sequence can be determined for the function execution request, the customized function execution sequence can be executed, and results of the execution can be returned. The customized function execution sequence can comprise an indication of execution order for a plurality of functions.