Short answer: The PDF processing concepts developers should understand before designing reliable image asset extraction under load are object-versus-render semantics, fidelity contracts, byte-and-pixel admission limits, bounded concurrency, deadlines, idempotency, and separate verification for assets and flattened pages. For a gaming backend, that distinction matters when a player-submitted PDF feeds both a filled, flattened form and a set of review thumbnails. The form output needs visual c...