Discover powerful techniques for efficiently refactoring legacy code in this guided demo conference talk. Learn to combine Combination Testing, Code Coverage guidance, and Provable Refactorings to achieve 100% test coverage and make significant code improvements without extensive reading or understanding. Apply these methods to the Gilded Rose Kata, transforming seemingly impossible tasks into manageable ones. Gain insights into commit notation, unit testing, combination approvals, test quality, and strategic code deletion. Master the art of cutting through complex codebases and emerge with cleaner, fully tested code in just over an hour.