That depends on how well the obfuscator works and scrambles your code. Does it rename ALL classes, variables, methods and constants to gobbledygook? Does it add

That depends on how well the obfuscator works and scrambles your code. Does it rename ALL classes, variables, methods and constants to gobbledygook? Does it add redundant code every now and then to add more confusion? If you do all that, then it becomes very difficult to crack even for advanced hackers. But ultimately it should be possible as obfuscation is based on a human logic (though executed by machines) - but it will certainly increase the needed difficulty and dedication to a considerable degree.