Expo SDK 56 speeds iOS builds

1/ Expo SDK 56 is the kind of release mobile teams notice in the inner loop, not just in feature lists. Expo says JavaScript exports are about 20% faster, iOS builds are roughly a minute quicker, and Android builds can be up to 2.8x faster. (expo.dev) 2/ Those numbers matter because Expo sits in the build-and-ship path for React Native apps targeting iOS, Android and web. When export and native build steps shrink, the cost of each test cycle drops with them. That is most visible on larger apps, where waiting on the toolchain can dominate actual coding time. (expo.dev) 3/ The timing also fits Expo’s recent direction. Expo SDK 53 enabled the `package.json:exports` field in Metro by default and introduced remote caching for local builds, while later changelog updates added build caching controls for EAS and Gradle caching for Android builds. SDK 56’s speed story looks like another step in the same push to reduce repeated work in the build pipeline. (expo.dev) 4/ On iOS specifically, Expo had already been teeing up shorter clean builds. In SDK 54, the company said React Native on iOS and its dependencies would ship as precompiled XCFrameworks, cutting RNTester clean builds from about 120 seconds to 10 seconds on an M4 Max in Expo’s test case, while warning app-level gains would vary by project. (expo.dev) 5/ That “your mileage may vary” caveat is why the developer anecdote attached to SDK 56 is useful. A post cited in the story said a 103,000-line app was updated in 30 minutes and saw a 45% iOS build speedup in real workloads after the upgrade. The point is less the exact number than the fact that at least one large app saw gains outside a benchmark harness. (x.com) 6/ For teams shipping iOS and macOS code from a shared JavaScript or React Native base, faster exports and builds change day-to-day behavior. Smaller waits make it cheaper to test a fix, retry a broken build, or validate a UI change on device. That tends to show up first in developer feedback loops rather than in end-user features. (expo.dev) 7/ SDK 56 is not only a performance release. Expo’s beta announcement said it also includes React Native 0.85.2 and React 19.2.3, and makes Expo UI’s SwiftUI and Jetpack Compose APIs stable. That means some teams will evaluate the release for platform and UI reasons even before the build wins are fully measured. (expo.dev) 8/ There is one practical wrinkle on iOS: Expo said on May 4 that the App Store version of Expo Go was still waiting for approval for newer SDK support, and that developers may need to use development builds, simulator installs or TestFlight paths for newer SDK versions. So the speed gains are real, but how quickly teams can try them may depend on their workflow. (expo.dev) 9/ The clean way to read this release is simple: Expo is spending engineering effort on build latency as a product feature. For React Native teams, especially ones with large iOS projects, that can be more valuable than a flashy API because it touches every commit. (expo.dev) 10/ If you’re evaluating whether SDK 56 is worth the upgrade, the key checks are straightforward: compare export time, clean iOS build time, incremental build time, and any Android cache hit improvements in your own CI and local setup. Expo’s published gains set the expectation; your project structure will decide the actual payoff. (expo.dev)