Mobile App Engineering

Builds and ships production React Native apps - architecture, navigation, list and startup performance against explicit budgets, native modules, and EAS release flow. Use when someone asks "why is my FlatList janky", "how do I speed up cold start", "should this be a TurboModule", "how do I set up EAS builds and OTA updates", or wants a React Native feature built to production quality. Do NOT use for Flutter apps - use flutter-widget-architect instead; do NOT use for offline-first sync and conflict resolution - use mobile-offline-sync instead; do NOT use for native-only iOS SwiftUI work - use swift-ui instead; for deep profiling sessions use mobile-perf-profiler.

Builds Android Jetpack Compose UI with hoisted state, unidirectional data flow, and recomposition-safe patterns backed by measured stability rules. Use when someone asks "build this screen in Compose", "where should this state live", "why does my LazyColumn stutter", or is writing Composable functions, ViewModel and StateFlow wiring, or fixing recomposition jank in Kotlin. Do NOT use when the screen targets Flutter - use flutter-widget-architect instead; for iOS declarative UI use swift-ui; for React Native screens use react-native-pro; and if jank persists after state fixes, profile with mobile-perf-profiler.

Architects Flutter widget trees and Riverpod or Bloc state so rebuilds are scoped, build() stays pure, and const widgets skip recomposition. Use when someone asks "why is my Flutter screen janky", "should I use Riverpod or Bloc", "my whole page rebuilds when one field changes", or is building or refactoring Flutter screens, wiring StatelessWidget/StatefulWidget, Consumer, or BlocBuilder. Do NOT use for Android Jetpack Compose UI - use jetpack-compose-builder instead; do NOT use for React Native - use react-native-pro instead.

Builds local-first mobile storage with an optimistic local store, durable mutation outbox, per-entity conflict-resolution rules, incremental pull, and idempotent background retry. Use when someone says "the app has to work offline", "how do I sync Room or SQLite or Realm with the server", "what happens when two devices edit the same record", or offline edits must reconcile with the server later. Do NOT use for paginating, caching, and refreshing read-heavy server lists - use pagination-and-sync-engineer instead; and do NOT build offline write support for strong-consistency operations like payments or inventory counts - disable those offline.

Wires native mobile push end to end on APNs and FCM - device-token lifecycle, permission priming and prompt timing, alert and silent payloads, the server send path, and tap routing in all app states. Use when someone says "add push to our app", "the notification never arrives", "how do I handle FCM token refresh", or is wiring the .p8 or service-account sender and handling notification taps. Do NOT use for writing the notification text and message strategy - use push-notification-copy instead; not for web/browser push (Web Push/VAPID), in-app banners, or platform notification dashboards; and hand navigation from a tapped payload into a specific screen to a deep-link router.

Diagnoses and fixes mobile jank, dropped frames, slow startup, and growing memory by capturing a trace or heap snapshot on a real device, isolating the single worst cost, fixing it, and re-measuring against the 16ms frame and cold-start budgets. Use when someone says "the app stutters when I scroll", "startup takes forever", "memory keeps climbing after navigating around", or the UI feels laggy on a real device. Do NOT use when the bottleneck is a website or web app (LCP, bundle size, slow endpoint or query) - use web-performance instead; for Compose recomposition fixes pair with jetpack-compose-builder; for Flutter widget architecture use flutter-widget-architect.

Produce a reproducible signing, versioning, and store-declaration pipeline so an iOS or Android build passes App Store Connect / Play Console submission. Use when building or uploading a distribution .ipa/.aab, fixing signing/provisioning-profile or entitlement errors, bumping CFBundleVersion/versionCode, filling App Privacy / Data safety forms or PrivacyInfo.xcprivacy, wiring Fastlane lanes, or diagnosing a store rejection. Do NOT use for general (non-mobile) release steps like changelogs, tagging, or backend deploys - use prepare-release instead; do NOT use for store listing titles, descriptions, or keywords - use app-store-copy instead.