Page 7 - React Native

react-native-web renders the same View, Text and ScrollView primitives used on iOS and Android as regular DOM elements in the browser. This article looks at how that translation actually works, where styling and platform APIs create real limits, and how much code genuinely ends up shared once navigation, native hardware access and layout details enter the picture.

An app that noticeably slows down after half an hour of use, or crashes on older devices, very likely has a memory leak. Unlike pure JavaScript code, where the garbage collector silently forgives many mistakes, React Native's actual memory footprint is shaped by both JavaScript-side and native references. This article covers the typical causes, unremoved event listeners, hanging timers, and problematic closures, and shows how to systematically find and fix leaks with Xcode Instruments and Android Studio Profiler.

Accessibility in a React Native app isn't a CSS afterthought like on the web, it requires deliberately set accessibilityLabel values, roles and a well thought out focus order from the very start. Ignoring these fundamentals effectively excludes screen reader users of VoiceOver and TalkBack from the app, and since the European Accessibility Act it also carries legal consequences.

Plain HTTPS trusts the entire operating system trust store, and that is exactly the gap rogue CAs, corporate proxies and tools like mitmproxy exploit. SSL pinning locks a certificate or public key directly into the app and turns intercepted traffic into a dead end for attackers, once certificate pinning and public key pinning are implemented cleanly for iOS and Android, tested properly and backed by a rollover strategy.

Implementing in-app purchases directly against StoreKit and Google Play Billing in a React Native app means duplicating every change to products, prices and receipt verification for both platforms. RevenueCat unifies both billing systems behind a shared API of offerings, entitlements and server-side receipt validation, letting paywall logic, purchase flow and subscription status live in a single React Native codebase.

Code signing decides whether a React Native app can even be installed on a test device, let alone published to the App Store or Play Store. Anyone who does not understand how a certificate, a provisioning profile, an app ID and a team fit together loses hours to cryptic build errors. This guide explains the full signing system for iOS and Android and shows how EAS Credentials and Fastlane match replace most of the manual effort.

Worklets are the foundation of Reanimated: small JavaScript functions transformed by a Babel plugin so they run directly on the UI thread, independent of how busy the JS thread is. Understanding why Reanimated is fast, and where runOnJS and runOnUI actually belong, requires knowing this execution model in detail, not just memorizing the finished hooks.

Jest testing in React Native covers unit tests for pure logic and hooks, plus component tests with React Native Testing Library that verify actual user behavior instead of matching implementation details. Set up correctly, with clean mocking, disciplined snapshots, and coverage thresholds in the CI pipeline, this testing layer catches most regressions before they ever reach a simulator.

A React Native app that talks to an IoT device over Bluetooth Low Energy has to handle scanning, pairing, permissions, and dropped connections robustly. This article walks through a complete Bluetooth integration with react-native-ble-plx, from the GATT hierarchy to production-grade reconnect logic.

Gestures alone only deliver raw data, real interactions only emerge once that data flows into animations in real time. This article shows how react-native-gesture-handler and Reanimated work together through shared values, so pan and pinch gestures turn into fluid animations directly and synchronously on the UI thread, illustrated with a swipeable card that springs back into place.