From the VRAIN institute at UPV, we have developed various advanced code debugging techniques, focusing on automatic and/or heavily assisted tools. We mainly consider techniques based on “slicing” and reversible debugging. While the former help us narrow down the lines of code where the error might be located, the latter are used to explore an execution step-by-step, both forward and backward. Debugging tools are the ideal complement to testing and validation techniques, as they assist in locating the origin of detected errors. This way, it is possible to reduce the times for detection, localization, and especially, correction of software errors, a crucial task in any environment where software is developed.