Offline-First Architecture
DATA › Offline
Building apps that read and write without network, syncing reliably when connectivity returns.
Offline-first is a senior-level system-design favorite because it forces you to reason about the data layer as the contract between UI and network, not just plumbing. Interviewers probe whether you make the local store the single source of truth, how you queue and reconcile writes, and how you keep the UI reactive and resilient while offline. Expect to defend trade-offs across write strategies, sync models, and conflict resolution.
What this covers
- Designing the local DB (Room) as the canonical single source of truth that all reads observe
- The NetworkBoundResource / stale-while-revalidate pattern: serve cache immediately, refresh in background
- Write strategies: online-only vs queued vs lazy (local-first) and when each fits
- Driving deferrable, retryable background sync with WorkManager and network constraints
- Conflict resolution approaches like last-write-wins with timestamps and server authority
- Reactive reads with Flow/StateFlow plus error handling (catch, LCE/loading-content-error state)
Study this topic
- Offline-First Architecture explained: the guided lesson
- 14 practice quiz questions
- 9 revision flashcards
- Offline-First Architecture interview questions and answers