Systems | Development | Analytics | API | Testing

Build tools have relied on it for years to avoid redoing work that hasn't changed. In React Native CI it's still a bit of a secret sauce: a fingerprint-based caching technique that can make your builds several times faster, yet one that surprisingly few teams have switched on. The premise is simple: most of the time you're only changing JavaScript, so most of the native modules are reusable.

Cross-platform builds promise rapid delivery through a shared codebase, yet QA teams encounter stubborn regression roadblocks across Android and iOS. React Native connects JavaScript threads to native host views via an asynchronous message channel. When test runners dispatch actions faster than native components finish rendering, automated assertions trigger false alarms without underlying code failures.

If you are a React Native engineer, your job isn’t typically about maintaining infrastructure. So “self-hosted OTA” can sound like a trap. Even if your Expo Update bill is hitting six figures, it’s easy to assume that self-hosting isn’t worth the potentially huge time sink. That fear is understandable, but it doesn’t have to play out that way.

Self-hosting OTA updates became common after App Center and CodePush shut down in 2025. CodePush had been the popular free option, but the remaining hosted services easily hitting five or six figure bills for popular apps. For staging-only or use with small user bases, self-hosting is fairly straight forwards. But, as the user base grows, the architecture can start to struggle and bolt on pieces are required.

React Native OTA tools in 2026 split across two clients, Expo Updates and CodePush-style, and two ways of running them, hosted or self-hosted. The clients are not interchangeable. You still need the matching SDK.

Until now, sending push notifications to a React Native app with Ably meant registering devices manually through the push admin API, usually from a server. The new plugin moves activation where it belongs: onto the device. We've added first class support for React Native apps receiving push notifications through the Ably PubSub JavaScript SDK.

React Native debugging poses particular challenges due to the framework’s cross-platform codebase, which combines JavaScript and native platform components. However, an effective React debugging regime will enable you to proactively fix issues in both production and development. Today’s post will give you the fundamentals to build that regime, showing you: Want to jump to a specific bit of knowledge? Here’s the full list of contents.

A React Native build is really two builds stacked on top of each other. On Android, Gradle compiles your Kotlin and Java, then drops down into cmake and ndk-build to compile the C++ that ships inside Hermes, Folly, ReactCommon, and your own turbo modules. On iOS, Xcode does the equivalent: Swift and Objective-C on top, the same C++ underneath via Clang. Two build systems, two languages on top, one shared set of C++ underneath.