--- title: "Real-Device Testing" description: "Test on physical iOS and Android hardware with agent-driven runs, where gestures, performance, and native integrations actually behave." url: https://www.callstack.com/services/real-device-testing updated: 2026-11-06T10:09:39.356Z --- # Real-Device Testing Test on physical iOS and Android hardware with agent-driven runs, where gestures, performance, and native integrations actually behave. _[Agentic Delivery](/agentic-delivery) › [AI-Driven QA & Testing](/capabilities/ai-driven-qa-testing)_ **Test where your users are: on hardware** Simulators lie about performance, gestures, and native integrations. We run agent-driven testing on physical devices through Agent Device, our open-source automation platform - locally or from any CI runner. [Add QA agent](#contact) · [How it works](#what-you-get) ## AI-Driven QA & Testing - Industry runs on our tooling · 50M+ OSS downloads / month - 100+ Enterprise projects delivered - React Foundation Founding Member · 300+ commits to React Native · Contributing since 2016 - Expensify uses agent-device for bug evidence. Its usage story covers collecting evidence from mobile apps and profiling. - ~6x Faster prototyping · 60+ Components mapped with full coverage · Figma · Claude · Server · Tailwind · Tokens · React · Cursor · ESLint - 3.7× Lower task cost vs Opus 5.5 - Testing Library · Testing utilities in our open-source toolkit for checking React Native behavior. ## What you get: Real hardware, wired into delivery. - **Physical device execution** Flows run on real iOS and Android hardware, not emulator approximations. - **Built on Agent Device** Our open-source, agent-agnostic platform: auditable, extendable, no vendor lock-in. - **Performance on device tiers** Startup, frame drops, and memory measured on the low-end hardware users actually own. - **Native integration coverage** Camera, biometrics, push, and deep links - the things simulators fake. - **On-prem or cloud devices** Your device lab or hosted hardware, matched to your security policy. - **CI-native runs** Real-device checks triggered from PRs and pipelines like any other job. **Stop trusting simulators.** Real-device coverage that runs from your CI and scales with agents. [Add QA agent](#contact) ## Scope → Build → Scale: Design QA that keeps delivery moving. ### Scope (1 WEEK) We select a product workflow, define where agents act, and agree the controls and success measures. - Workflow and owners defined - Baseline and controls agreed - Token budgets confirmed ### Build (1-12 MONTHS) We connect context, agents, and verification to your tools, then run the workflow on your product backlog. - Running on your product backlog - Speed and quality measured - Business impact validated ### Scale (AS NEEDED) We document the workflow, transfer ownership, and extend it across teams and products based on results. - Your team owns the workflow - Expand based on results - Full knowledge handover ## What shipping at AI speed looks like. - [Migrating Questrade Edge Mobile to a Faster, More Scalable Architecture](/case-studies/migrating-questrade-edge-mobile-to-a-faster-more-scalable-architecture): 33% fewer re-renders across most features - [Building an Agentic SDLC for a Web Launch in Under One Month](/case-studies/building-an-agentic-sdlc-for-a-web-launch-in-under-one-month): 3x estimated delivery acceleration - [Engineering AI Loops for a Cross-Platform Design System](/case-studies/engineering-ai-loops-for-a-cross-platform-design-system): 60+ components mapped with full Code Connect coverage - [Enhancing Application's Performance for Expensify](/case-studies/enhancing-applications-performance-for-expensify): 5x faster message sending time **Stop trusting simulators.** Real-device coverage that runs from your CI and scales with agents. [Add QA agent](#contact) > Their engineers proved to be a crucial part of our mobile app relaunch project. > > — Brian Aznar, Engineering Director / Major League Soccer We’ll connect you with the right expert within 24 hours. ## Let’s find the right path for your product. Still have questions? Whether you’re planning new work or unblocking an existing product, we’ll help you choose the right path forward. **Should we build a device lab or use hosted devices?** Depends on volume and policy. Owned labs win on cost at scale and on data control; hosted wins on elasticity. Hybrid setups are common, and we design both. **How many devices do we need?** Fewer than most teams assume. A small matrix covering your top OS versions and performance tiers catches the large majority of device-specific issues. **How do you deal with flaky hardware?** Health checks, automatic re-provisioning, and quarantine for misbehaving devices - lab reliability is an infrastructure problem, and we treat it as one. **What about iOS provisioning and signing?** We automate certificate and profile management as part of the setup. It is painful exactly once. **What does Agent Device cost?** It is open source. You pay for the engineering to build the infrastructure around it, not for a per-device license. **Does this cover TV and desktop?** Yes. Agent Device automates iOS, tvOS, macOS, Android, and Android TV, so coverage follows wherever your product ships. [Book consultation](#contact) ## Open source - [Agent Device](https://agent-device.dev/): CLI to control iOS and Android devices for AI agents - [React Native Testing Library](https://github.com/callstack/react-native-testing-library): Simple and complete React Native testing utilities that encourage good testing practices - [Reassure](https://github.com/callstack/reassure): Performance testing companion for React and React Native - [React Native Harness](https://github.com/callstackincubator/react-native-harness): Harness brings Jest-style tests to real native environments so you can test TurboModules like you would test your React Native app: with JavaScript. - [Rozenite](https://github.com/callstackincubator/rozenite): Plug-and-play panels for React Native DevTools. Install, enable, and start debugging in minutes. Insights ## Worth your time, by engineers. [Explore Insights](https://www.callstack.com/insights) - [How AI Agents Can Cut Manual QA by 30%](https://www.callstack.com/blog/how-ai-agents-can-cut-manual-qa-by-30) (Oct 30 · Article): Two days waiting for QA can turn a small fix into another round of rebasing and context switching. See how a workflow using AI agents could cut manual QA effort by 30% across mobile, web, and TV, and learn how to validate the gains. - [Give QA Agents the Controls They Need With Appduct](https://www.callstack.com/blog/give-qa-agents-the-controls-they-need-with-appduct) (Oct 20 · Article): Appduct lets AI QA agents call functions registered by your team inside a running app. This article illustrates how an adjustable app clock and a simulated invitation event can prepare conditions for UI checks. - [Agentic Mobile Testing With e2e and agent-device](https://www.callstack.com/blog/agentic-mobile-testing-with-e2e-and-agent-device) (Oct 13 · Article): TesterArmy's e2e uses agent-device to drive mobile tests on iOS and Android. This article walks through goal-based actions, deterministic checks, the mobile engine, and replay caching, then shows how to initialize a test setup. Cached agent.act steps skip model calls; agent.assert continues to evaluate the current screen. - [Introducing Mobile Dev: full mobile dev tooling right in your Codex app](https://www.callstack.com/blog/introducing-mobile-dev-full-mobile-dev-tooling-right-in-your-codex-app) (Oct 2 · Article): Mobile Dev brings live device previews, annotations, logs, and performance profiling into Codex. Explore the initial preview for iOS and Android development, with built-in agent-device support. - [Exploring Jev for AI-Driven QA with agent-device](https://www.callstack.com/blog/exploring-jev-for-mobile-qa-with-agent-device) (Sep 17 · Article): Jev is a model from TypeSafe that chooses between predefined options instead of generating text. We paired it with agent-device to explore what that approach could mean for AI-driven QA: reading app state, selecting actions, and checking the result. We walk through our proof of concept, how the two tools work together, and a recorded run that took 14 seconds and cost $0.0023 in model inference. - [Automating Mobile QA With Cloud Agents](https://www.callstack.com/blog/automating-mobile-qa-with-cloud-agents) (Aug 4 · Article): Code review and green CI checks do not prove a mobile app still works. Learn how cloud agents, agent-device, and runtime evidence can verify app behavior before merge. - [3 Minutes With an Agent, 9 Seconds on Replay](https://www.callstack.com/blog/3-minutes-with-an-agent-9-seconds-on-replay) (Jul 30 · Article): Agent-device v0.20 turns known mobile journeys into scripts that agents can replay in seconds without further model calls. This article reports the experiments behind that workflow, based on 20 repeated runs, 38 Maestro flows, and 36 repair trials. It maps out when a task calls for settled observations, deterministic replay, live execution, repair, or a full re-recording as an app changes. It also covers how to validate repaired flows, prevent plausible but incorrect actions, and measure performance under realistic load. - [Introducing Sniffler: Run only the E2E tests your changes can affect](https://www.callstack.com/blog/introducing-sniffler-run-only-the-e2e-tests-your-changes-can-affect) (Jul 6 · Article): Sniffler helps JavaScript and TypeScript teams run only the E2E tests affected by a change. It traces import and export relationships and reduces unnecessary CI work without asking teams to give up test coverage. - [How Expensify Uses Agent-Device for Mobile Bug Evidence and Performance Profiling](https://www.callstack.com/blog/how-expensify-uses-agent-device-for-mobile-bug-evidence-and-profiling) (Jun 26 · Article): This article shows how we use agent-device with the Expensify app across three everyday mobile workflows: verifying bug fixes with recorded before/after evidence, measuring Sentry performance spans, and profiling React renders. - [Writing Custom Renderers for React](https://www.callstack.com/blog/writing-custom-renderers-for-react) (Jun 24 · Article): React Test Renderer’s deprecation forced React Native Testing Library to find a long-term replacement. In this article, Maciej Jastrzębski explains what it took to build a new JavaScript-only test renderer for RNTL and uses that process to show how React renderers actually work. It’s a practical look at React elements, Fiber, host instances, HostConfig, and React Reconciler for anyone who wants a clearer mental model of how JSX becomes UI. - [How Skillgym Helps You Verify Agent Skills Still Work After Every Change](https://www.callstack.com/blog/how-skillgym-helps-you-verify-agent-skills-still-work) (Apr 17 · Article): Small edits to a SKILL.md can change agent behavior in ways that are hard to spot manually. This article shows how skillgym helps you test skills against real agent runners, validate the right behavior, and catch regressions before they reach production. - [Agent React DevTools: Give AI Agents Access to React Internals](https://www.callstack.com/blog/agent-react-devtools-give-ai-agents-access-to-react-internals) (Apr 14 · Article): Agent React DevTools gives AI agents direct access to the React component tree, state, and performance data. Instead of relying only on UI snapshots, agents can now inspect what happens inside React and debug issues with proper context. This enables more reliable QA, better performance analysis, and deeper automation for React and React Native apps. - [How We Optimized Agent Device for Mobile App Automation](https://www.callstack.com/blog/how-we-optimized-agent-device-for-mobile-app-automation) (Apr 3 · Article): AI agents are powerful tools for mobile automation, but running them can get expensive and slow if they consume too many tokens. In this post, we break down how we optimized Agent Device to cut LLM token usage in half and speed up execution by 33%. - [Agent Device: iOS & Android Automation for AI Agents](https://www.callstack.com/blog/agent-device-ai-native-mobile-automation-for-ios-android) (Feb 17 · Article): This article introduces agent-device, a new CLI for automating mobile UI workflows with AI agents. It explains what the tool is, how it helps developers with token-efficient snapshots and repeatable interactions, and why Callstack is building it to bridge exploratory agent behavior with deterministic replay across iOS and Android. - [Introducing React Native Harness: Fast, Real-Device Testing for Native Modules](https://www.callstack.com/blog/introducing-react-native-harness-fast-real-device-testing-for-native-modules) (Oct 15 · Article): Introducing React Native Harness: a new way to test native modules directly on real devices and emulators. It brings together the speed and simplicity of Jest with the realism of on-device execution, giving developers a powerful, CI-ready tool to validate native behavior with ease. Harness makes it simple to ensure your native code works exactly as intended across every platform. - [From Unit to E2E: A Guide to Testing React Native TV in 2026](https://www.callstack.com/blog/testing-react-native-tv-apps) (Oct 3 · Article): While many React Native testing tools like Jest and Appium are transferable to TV development, they lack built-in support for remote control interactions. For component tests, this means the standard library helpers are insufficient, requiring developers to build their own mocks that emit low-level hardware key events to simulate D-pad focus changes. For end-to-end tests, it requires distinct configurations and commands for native versus web-based TV platforms. This article explains how to create these custom JS test helpers from scratch and how to set up Appium to run automated E2E tests on emulators, real devices, and device farms. - [Type-Checking React and Redux (+Thunk) with Flow - Part 1](https://www.callstack.com/blog/type-checking-react-and-redux-thunk-with-flow-part-1) (Feb 5 · Article): Flow is a static type checker for JavaScript that can help catch errors in React code. This guide walks through practical examples of using Flow to type check React components, including stateless functions, class components, transferring props, and higher-order components. - [Using AI to Write Tests for React Components](https://www.callstack.com/blog/using-ai-to-write-tests-for-react-components) (Apr 25 · Article): Writing tests for UI can be tedious, but it's critical for ensuring code quality. This guide explores how AI tools like GitHub Copilot and ChatGPT can help make the process more efficient by suggesting test code for React components. - [Time to Detox](https://www.callstack.com/blog/time-to-detox) (Oct 5 · Article): Detox is a new end-to-end testing library for React Native that allows you to simulate user interactions and make assertions on the app's interface. This guide walks through how to set up Detox with Jest and write your first tests to check for expected text and behavior. - [Testing With React Native Accessibility Snapshot](https://www.callstack.com/blog/testing-with-react-native-accessibility-snapshot) (Jun 23 · Article): Adding accessibility tests to your React Native app doesn't have to be a chore. This guide walks through setting up AccessibilitySnapshot, simplifying test creation, and automating the process with GitHub Actions. - [Testing a React App With Cypress](https://www.callstack.com/blog/testing-react-app-with-cypress) (Nov 6 · Article): Cypress is a new open-source testing tool that makes it fast and easy to write end-to-end tests for web apps. We walk through setting up Cypress to test core auth flows like login and logout in a real React app. - [Testing Your React Native Apps](https://www.callstack.com/blog/testing-your-react-native-apps) (May 3 · Article): Snapshot testing can save you hours of headache when upgrading React Native apps. This step-by-step guide shows you how to set up snapshot tests for iOS, capture reference images, and validate UI changes at a glance. - [Testing React Native Apps in the Cloud - Part 2](https://www.callstack.com/blog/testing-react-native-apps-in-the-cloud-part-2) (Oct 29 · Article): Tired of waiting for tests to run on your local machine? This guide walks through how to set up cloud testing for React Native apps using XCUITest and AppCenter. You'll learn how to create test suites, submit your app, and verify the results across multiple devices. - [Testing React Native With the New Jest - Part II](https://www.callstack.com/blog/testing-react-native-with-the-new-jest-part-2-redux-snapshots-for-your-actions-and-reducers) (Sep 29 · Article): Testing Redux reducers and actions in React Native doesn't have to be tedious. This guide shows how to use Jest snapshots to easily capture the expected output of your Redux code, simplifying the process of writing and maintaining tests. - [Testing React Native With the New Jest - Part I](https://www.callstack.com/blog/testing-react-native-with-the-new-jest-part-1-snapshots-come-into-play) (Sep 9 · Article): Writing tests for React Native apps doesn't have to be painful. We explore how Jest's new snapshot testing feature makes it easy to catch bugs and verify your UI stays consistent as you iterate, without tedious manual comparisons. - [Testing React Native Apps In the Cloud - Part 1](https://www.callstack.com/blog/testing-react-native-apps-in-the-cloud-part-1) (Oct 22 · Article): Testing React Native apps on real devices can be challenging, especially for rare or older models. Cloud testing services like Microsoft's AppCenter allow you to easily run tests on hundreds of iOS and Android devices in parallel, without needing physical devices. This guide walks through how to set up a React Native project and configure AppCenter to run tests in the cloud using native frameworks like XCUITest. - [Testing Expo Web3 Apps With Wagmi and Anvil](https://www.callstack.com/blog/testing-expo-web3-apps-with-wagmi-and-anvil) (Jun 12 · Article): Writing tests for web3 apps in React Native doesn't have to be daunting. This guide walks through configuring your project with Anvil, Wagmi, Viem, and Web3Modal, and shares practical tips for testing wallet connections, transactions, and edge cases without sacrificing speed or reliability. - [Run Tests for Key Pieces of Your App](https://www.callstack.com/blog/run-tests-for-key-pieces-of-your-app) (May 12 · Article): Writing automated tests is key to shipping React Native apps with confidence. This guide shares practical tips for testing the most important parts of your app, from unit testing components to end-to-end flows, without getting bogged down trying to achieve 100% coverage. - [React Native Testing Library With Redux](https://www.callstack.com/blog/react-native-testing-library-with-redux) (Aug 5 · Article): Testing Redux with React Native Testing Library doesn't have to be complex. This guide walks through how to set up a custom render function to test your connected components in a real Redux environment, without relying on implementation details. - [React Native Testing Library Turns Into Testing Library](https://www.callstack.com/blog/react-native-testing-library-turns-into-testing-library) (Jan 10 · Article): React Native Testing Library and Native Testing Library have officially merged into a single library under the Testing Library family. The new @testing-library/react-native package combines the best of both libraries while providing a smooth migration path for existing users. - [React Native Testing Library 2.0 - What’s New?](https://www.callstack.com/blog/react-native-testing-library-2-0) (May 28 · Article): React Native Testing Library 2.0 is out with new features to improve testing React Native components. It adds automatic cleanup, async act support, and scoped queries with the within operator. The release also removes some deprecated APIs and improves compatibility with community projects. - [React Native Android Accessibility Tips](https://www.callstack.com/blog/react-native-android-accessibility-tips) (Sep 12 · Article): Writing accessible React Native apps for Android takes extra care. This guide shares practical tips to fix common issues like inline text links, icon sizes, text input placeholders, header titles, and WebView styling to ensure your app works well for all users. - [React Native Accessibility: What, Why, and How?](https://www.callstack.com/blog/react-native-accessibility) (May 18 · Article): Accessibility in mobile apps is about enabling equal access for people with disabilities. This guide shares practical tips for implementing accessibility in React Native, from design considerations like color contrast and font readability to testing with screen readers and other assistive tools. - [Performance Regression Testing for React Native](https://www.callstack.com/blog/performance-regression-testing-react-native) (Feb 2 · Article): As your React Native app grows, performance tends to degrade over time. This guide shows how to catch performance regressions early with Reassure, a new open-source tool for automating performance tests in CI/CD pipelines. - [Merge of React Native Testing Libraries](https://www.callstack.com/blog/merge-of-react-native-testing-libraries) (Jul 30 · Article): The React Native community has been using two separate testing libraries with near-identical interfaces. After much discussion, the libraries are finally merging into a single official package: @testing-library/react-native. The merge brings together the best of both worlds while making the migration process as smooth as possible. - [Introducing E2E Tests to React Native Core](https://www.callstack.com/blog/introducing-e2e-tests-to-react-native-core) (Sep 12 · Article): React Native's core team recently introduced automated end-to-end (E2E) tests to improve the framework's reliability and catch regressions early. The effort was a collaboration between engineers from Callstack, Microsoft, and Meta, who worked together to research, propose, and implement a robust E2E testing setup using Appium, WebDriverIO, and Jest. - [From Enzyme to React Native Testing Library: How I Changed My Way of Unit Testing](https://www.callstack.com/blog/unit-testing-from-enzyme-to-react-native-testing-library) (Jul 8 · Article): Writing unit tests for React components can be tricky, especially when checking implementation details instead of functionality. This article shows how to refactor tests using React Native Testing Library to make them more effective and focused on what users actually interact with. - [Continuous App Performance Monitoring Made Simple With Reassure](https://www.callstack.com/blog/app-performance-monitoring) (Sep 21 · Article): Tired of performance regressions slowing down your React or React Native app? Reassure is an open source library that makes it easy to write performance tests, integrate them into your CI, and catch issues before they hit production. - [Consistently Improve App Performance With DMAIC and Reassure](https://www.callstack.com/blog/consistently-improve-app-performance-with-dmaic-and-reassure) (Mar 11 · Article): Keeping React Native apps performant as they grow can be challenging. This guide walks through using the DMAIC process to consistently identify and fix performance issues, and catch regressions early with automated testing tools like Reassure. - [A Comprehensive Guide to Mock Service Worker (MSW)](https://www.callstack.com/blog/guide-to-mock-service-worker-msw) (Sep 27 · Article): Tired of flaky tests and complex mocking? Mock Service Worker (MSW) lets you intercept real network requests in your tests, making it easy to test components that rely on APIs. We share best practices and advanced techniques for using MSW effectively in larger projects. - [Who Tests AI-Written Code? Inside TesterArmy With Szymon Rybczak](https://www.callstack.com/podcasts/who-tests-ai-written-code-inside-testerarmy-with-szymon-rybczak) (Oct 12 · Podcast): Szymon Rybczak explains how TesterArmy tests web and mobile apps with AI agents, creates test plans for pull requests, and fits into QA workflows. - [How AI Is Changing React Native Development and Testing](https://www.callstack.com/podcasts/how-ai-is-changing-react-native-development-and-testing) (May 13 · Podcast): Zack Ebenfeld joins React Universe On Air to talk about how AI is changing React Native workflows, testing, QA, and day-to-day engineering work. - [What's New in Reassure 1.0](https://www.callstack.com/podcasts/whats-new-in-reassure-1-0) (Jul 17 · Podcast): Find out how to monitor React and React Native performance better than ever before with Reassure's new features. - [Reassure - Open Source Tool Measuring Performance Regression](https://www.callstack.com/podcasts/reassure-performance-regression-measurement-tool) (Jul 28 · Podcast): Explore Reassure, an Open Source tool for measuring performance regression in React Native apps. - [React Native News and App.js Conf](https://www.callstack.com/podcasts/coffee-talk-4-react-native-news-app-js-conf) (Jun 22 · Podcast): Join Michał Pierzchała and Abi Thiao as they discuss the most interesting talks at App.js Conf 2022 and other React and React Native news. - [Look into the Future of React Native Testing Library](https://www.callstack.com/podcasts/look-into-the-future-of-react-native-testing-library) (Aug 11 · Podcast): The first episode of React Universe On Air (formerly known as The React Native Show) provides insights into React Native Testing Library. Mike and his guest give a quick glimpse into the very concept of Testing Library and tell the story behind React Native Testing Library. - [Introducing E2E Tests to React Native Core](https://www.callstack.com/podcasts/introducing-e2e-tests-react-native-core) (Aug 23 · Podcast): This episode of the React Native Show dives into the recent introduction of End-to-End (E2E) testing in RNTester. Join us as we unpack the thought process, technical considerations, and practical implementation of this new approach to testing in React Native. - [Automating Mobile QA with Cloud Agents](https://www.callstack.com/events/automating-mobile-qa-with-cloud-agents-2) (Oct 7 · Talk): Michał Pierzchała shows how cloud-based QA agents can test real iOS and Android user flows and bring screenshots, recordings, and logs into pull requests. - [Behavior Review for AI-Native Delivery](https://www.callstack.com/events/behavior-review-for-ai-native-delivery) (Jul 21 · Webinar): AI can increase code output faster than teams can verify the real app. See why behavior review matters before merge. - [Giving AI Agents Hands: Mobile Feedback Loops with Agent Device](https://www.callstack.com/events/giving-ai-agents-hands-mobile-feedback-loops-with-agent-device) (Jun 12 · Talk): Mike Grabowski will speak at React Summit 2026 about Agent Device, Callstack’s agent-native automation layer for giving AI coding agents a practical feedback loop across mobile, TV, and desktop apps. - [Mobile QA with Cloud Agents at AI Coding Summit London](https://www.callstack.com/events/mobile-qa-with-cloud-agents-at-ai-coding-summit-london) (Jul 6 · Talk): Michał Pierzchała will speak at AI Coding Summit London 2026 about mobile QA agents for iOS and Android pull request workflows. - [Callstack x Expo AI Meetup](https://www.callstack.com/events/callstack-x-expo-ai-meetup) (Jun 3 · Meetup): Join Callstack and Expo in San Francisco for practical talks on AI-native mobile development, Expo Agent, Cloud Agents and autonomous mobile QA. - [Automating Mobile QA with Cloud Agents](https://www.callstack.com/events/automating-mobile-qa-with-cloud-agents) (Jun 17 · Talk): Michał Pierzchała will present Automating Mobile QA with Cloud Agents at Ship London on 17 June 2026. - [Agent Device, AI workflows, and mobile testing in practice](https://www.callstack.com/events/agent-device-ai-agents-meet-mobile-automation) (Mar 19 · Live Stream): A discussion on Agent Device, AI-driven workflows, and testing mobile apps using simulators and accessibility data. - [Write Once, Test Everywhere: Cross-Platform Testing for React Native](https://www.callstack.com/events/write-once-test-everywhere-cross-platform-testing-for-react-native-2) (Dec 9 · Talk): Join Szymon Chmal at WarsawJS #133 to explore cross-platform testing in React Native with a new approach powered by React Native Harness. - [Testing Native Modules Reliably With JavaScript](https://www.callstack.com/events/testing-native-modules-reliably-with-javascript) (Nov 14 · Talk): Learn how React Native Harness bridges the gap between mocking and E2E testing: real device tests, full native access, Jest-style simplicity. - [React Native Harness, Next.js 16 Beta & Remix v3](https://www.callstack.com/events/react-native-harness-deep-dive) (Oct 16 · Live Stream): This week’s Live Dev Session dives into React Native Harness with Szymon Chmal, explores the Next.js 16 Beta and Remix v3 “pre-drop,” and breaks down the biggest React and React Native updates from the community and React Alicante 2025. - [Write Once, Test Everywhere: Cross-Platform Testing for React Native](https://www.callstack.com/events/write-once-test-everywhere-cross-platform-testing-for-react-native) (Oct 4 · Talk): Cross-platform testing in React Native made simple: a lightweight architecture to run and extend tests on any JavaScript-powered platform. - [Automated Performance Regression Testing With Reassure](https://www.callstack.com/events/automated-performance-regression-testing-with-reassure) (Feb 24 · Talk): Developers often fix performance issues in React apps, but this is unsustainable and prone to regressions. Reassure, a testing library, helps spot problems before production, enhancing automated testing suites. - [How to Run E2E Tests on Every PR and Don’t Burn All Your CI Credits](https://www.callstack.com/events/how-to-run-e2e-tests-on-every-pr-and-dont-burn-all-your-ci-credits) (Apr 1 · Talk): End-to-end tests are notoriously slow and costly, especially in mobile development. This talk introduces new tools and techniques to make E2E testing fast and efficient, so you can run tests on every pull request without draining CI resources.