This question evaluates system architecture and backend–client design competencies, including viewport-based fetching, cross-module deduplication, pagination/continuation tokens, caching and storage strategies, personalization and experimentation integration, and observability for low-latency, high-QPS services in the System Design domain.
Design the backend + client interaction to support viewport rendering for a streaming service’s home page (rows of videos/tiles).
Explain APIs, data flow, storage/caching, deduplication strategy, pagination/continuation tokens, and how you handle edge cases (e.g., content removed mid-scroll, retries, personalization model updates).