Mobile Design Rounds https://mobiledesignrounds.com/ 2026-10-13T00:00:00Z Mobile system design case studies for Android and iOS engineers Design a chat app https://mobiledesignrounds.com/mobile-system-design/chat-app/ 2026-10-13T00:00:00Z Outbox, idempotent sends, WebSocket and push sync. Design a news feed https://mobiledesignrounds.com/mobile-system-design/news-feed/ 2026-10-13T00:00:00Z Pagination, optimistic writes, cache invalidation. Design photo backup and file sync https://mobiledesignrounds.com/mobile-system-design/photo-file-sync/ 2026-10-13T00:00:00Z Resumable uploads, block-level sync, conflicts. Design a pagination library https://mobiledesignrounds.com/mobile-system-design/pagination-library/ 2026-10-13T00:00:00Z Library API, generics, request prioritization. Design an image loading library https://mobiledesignrounds.com/mobile-system-design/image-loading/ 2026-10-13T00:00:00Z Memory and disk caches, decoding, cancellation. Design a hotel or ride booking app https://mobiledesignrounds.com/mobile-system-design/booking-app/ 2026-10-13T00:00:00Z Holds, time sync, payments, search. Design a stock ticker app https://mobiledesignrounds.com/mobile-system-design/live-ticker/ 2026-10-13T00:00:00Z Streaming updates, buffered UI, always-online. Design a video streaming app https://mobiledesignrounds.com/mobile-system-design/video-app/ 2026-10-13T00:00:00Z Prefetching, adaptive bitrate, playback state. Design an analytics SDK https://mobiledesignrounds.com/mobile-system-design/analytics-sdk/ 2026-10-13T00:00:00Z Batching, persistence, privacy, versioning. Design a push notification SDK https://mobiledesignrounds.com/mobile-system-design/push-sdk/ 2026-10-13T00:00:00Z Token lifecycle, delivery, deep links. Staff-level mobile system design: what the round tests https://mobiledesignrounds.com/guides/staff-mobile-loop-guide/ 2026-10-13T00:00:00Z How staff answers differ from senior ones, what interviewers can observe, and a four-week practice plan. Offline-first mobile system design: one model, six case studies https://mobiledesignrounds.com/guides/offline-first-hub/ 2026-10-13T00:00:00Z The official offline-first model applied to chat, feed, upload, booking, analytics and push. Native vs cross-platform: write the decision record https://mobiledesignrounds.com/guides/native-vs-cross-platform-decision-guide/ 2026-10-13T00:00:00Z A staff-level ADR for a framework bet: criteria, the assumption that flips it, migration, parity tests, orphaned libraries, rollback, and a free template.