Abstract: A method and system for modifying computer program logic with respect to a predetermined aspect, comprising (a) before run time: analyzing compiled computer program logic of a module for processes involving the predetermined aspect before run time, substantially without decompilation or reference to computer program source code; and storing a set of modifications relating to computer program logic modifications of the module relating to the predetermined aspect; and (b) at run time: based on the stored set of modifications, selectively transferring program control from the module to a separate logical structure, executing modified logical operations with respect to the predetermined aspect, and subsequently returning program control to the module. The predetermined aspect may be, for example, a data type, algorithm type, or interface specification.