# Design a Performant Frontend News Feed Design a React news feed with rich text, mentions and hashtag hover cards, pagination, offline behavior, virtualization, and clear application/feed/feed-item component boundaries. ### Constraints & Assumptions - Feed items have stable IDs and may update. - Long feeds must not render every item. ### Clarifying Questions to Ask - Cursor or offset pagination? - What offline actions are supported? ### What a Strong Answer Covers - Normalized data, cursors, safe rich text, hover data, caching, virtualization, and render control. ### Follow-up Questions - How is scroll position restored? - How are optimistic actions reconciled?