A method is disclosed for recording and replaying computer programs. In one embodiment, a method of modifying a computer program to support recording execution, comprises the computer-implemented steps of receiving an executable application binary; modifying the executable application binary by adding one or more proxy code elements to result in creating a modified application binary, wherein upon execution of the modified application binary, the one or more proxy code elements create and store recorded information representing all non-deterministic events that occur during the execution. For example, asynchronous callbacks and thread context switches are recorded and can be replayed.