Certification prep has a supply problem: official practice exams are few, expensive and quickly memorized — after the second pass you're recognizing answers, not testing knowledge, which is precisely the failure mode practice exists to prevent. Meanwhile question banks of unknown quality sell subscriptions on the anxiety.

The raw material for unlimited practice is sitting in the open: every serious certification has a review-video ecosystem — instructors walking through domains, exam-cram sessions, topic deep-dives. Each one is a question bank that hasn't been asked yet. Turn the videos into questions and the supply problem inverts: fresh practice, on demand, from content whose quality you can verify.

deep_search finds the ecosystem's best: review and cram content for your certification, quality-filtered — high_density and factual verdicts sort the instructors who teach from the ones who pad, and the level filter matches material to where you are in prep.

run_youtube_tool's quiz-generator converts each video into practice: questions drawn from what the instructor actually covered, fresh every run. Weak domain? Search that topic's deep-dives and quiz against those specifically. The loop — find strong material, generate questions, attack the misses — is the active-recall engine cert prep always wanted, with supply that never runs out and never gets memorized.