Expo is a mobile infrastructure that lets developers create cross‑platform apps using a single codebase. It supports React Native, Swift, Jetpack Compose, and Kotlin, and it is aimed at teams that need rapid iteration and reliable delivery. What sets Expo apart is its end‑to‑end workflow: a CLI, cloud simulators, and a CI/CD pipeline that run tests on every change, plus over‑the‑air updates and built‑in performance monitoring. The platform also offers a library of production APIs and a community of over 3 million developers.