A system, method, and computer program product is disclosed that for debugging errors in software code. According to some approaches, techniques are provided for performing on-the-fly switching from compiled to interpretive debugging for a software program. The test starts with compiled code, and when it needs to stop for debugging, the debugging occurs in interpretive mode. Once debugging has concluded, the execution can switch back to compiled mode. In this way, the debugging activities can achieve the speed and efficiency of using compiled optimized executables, while still being able to allow debugging without performing any recompilations.