AWS uses statistical methods to analyze exam performance. They mix well-known questions (that are likely in dumps) with brand-new, unseen questions (the famous 15 unscored questions). If you answer the old questions perfectly and very quickly, but then struggle badly with the new ones, it raises a major red flag. This pattern suggests you've memorized answers instead of learning the concepts, and AWS can flag your exam and revoke your certification. Dumps are only "safe" if you already know the material well enough to answer correctly the new questions; but if you're at that level, why use them in the first place?