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FE System DesignBeginner40 minutes
Infinite Scroll News Feed
Design a high-performance infinite feed with virtualization, cursor pagination, caching, and scroll restoration.
LLM-friendly summary
A frontend architecture problem focused on infinite scrolling, virtualization, cursor pagination, and long-session memory management.
Scenario
A social feed becomes laggy after long sessions, loses scroll position on navigation, and shows duplicate posts under load.
What you need to design
- 1Handle 10,000+ items without DOM bloat.
- 2Choose between cursor-based and offset-based pagination.
- 3Restore scroll position after returning from detail pages.
- 4Manage memory for long sessions and media-heavy content.
- 5Deal with dynamic item heights and expansion.
Concepts
VirtualizationPaginationMemory ManagementScroll Restoration
Skills
Performance OptimizationData FetchingState Management
What good solutions are evaluated on
- - Virtual list architecture
- - Pagination and caching strategy
- - UX quality under long sessions
- - Memory and rendering trade-offs
Ready to practice this yourself?
Open the interactive AlgoReason workspace to sketch the architecture, write notes, and submit for AI evaluation.