Your 2026 Mobile Stack Is Modern Everywhere Except Testing

I spent 6 months talking to mobile engineers about their tooling. Flutter or React Native on the frontend. Supabase or Firebase on the backend. GitHub Actions for CI/CD. Mixpanel for analytics. Sentry for crash reporting. Every layer modern, maintained, actually pleasant to work with. Then I'd ask about testing. The energy would shift. Appium suites held together by brittle XPaths and Thread.sleep(). Espresso on Android, XCUITest on iOS same user flow, written and maintained twice. Flakiness rates sitting at 15-20%, sometimes spiking to 25% on real devices. One mobile lead estimated $200K/year in engineering time just on test maintenance not catching bugs, but fixing selectors that broke because someone changed an accessibility label or moved a component one level deeper in the hierarchy. Some teams just stopped writing tests altogether. Fell back to manual QA for critical flows. Not because they wanted to because the testing experience was so painful that false failures every morning