Design viewport dedup for Netflix home page

Design the above-the-fold (initial viewport) rendering for the Netflix home page so that all cells displayed in the first screen contain unique shows with no duplicates across rows or within a row. Describe the data model for rows and candidate items, personalization inputs, and constraints (e.g., row themes, editorial pins, maturity limits). Propose an algorithm to select and place items to satisfy deduplication while maximizing relevance, including conflict resolution, backfill strategy, and a latency budget suitable for client-side or server-side rendering. Explain how you would handle partial data, caching, and loading more items as the user scrolls, and how you would measure impact.