mobile-platform-architecturelisted

# Mobile Platform Architecture Code that works perfectly in a mobile simulator with a stable connection and an app that never gets backgrounded tells you almost nothing about how it behaves in the field. This skill designs against the actual constraints mobile OSes impose, not the friendlier development environment. ## Step 1 — Decide offline-first vs. online-only, explicitly If offline support is needed, define the sync strategy up front: last-write-wins, a CRDT-based merge, or manual conflict resolution surfaced to the user — and state explicitly what happens when a local-only change collides with a remote change made elsewhere. "We'll figure out conflicts later" is how sync bugs become the app's most reported issue. ## Step 2 — Design against real background-execution limits Both major mobile platforms impose hard limits and kill policies on background work — a naive background thread or timer will not simply keep running. State exactly what genuinely needs to run in the background (sync, notifications, location updates) and design it against the platform's actual scheduled/deferred-execution mechanisms, not an assumption that background work behaves like a server process. ## Step 3 — Define bridge/platform-channel boundaries deliberately (cross-platform frameworks) For any cross-platform framework, decide explicitly what crosses the native/framework bridge and account for the serialization cost of doing so on each crossing. Distinguish what genuinely needs a native