The Expo build process can be broken down into several steps:

  1. Creating a build profile: The first step is to create a build profile, which specifies the configuration options for the build. This can be done through the Expo CLI using the expo build:android or expo build:ios commands. The build profile specifies things like the app name, bundle identifier, and distribution options (such as whether to build a development or production version of the app).

  2. Packaging the app: Once the build profile is created, Expo will package the app's code and assets into a binary file that can be installed on a device. For Android, this is an APK file, and for iOS, it's an IPA file.

  3. Building the app: After the app is packaged, Expo will submit it to the appropriate app store for building. This involves compiling the code, linking any necessary libraries, and signing the binary with a certificate. This step is handled by the app store's build servers, so it may take some time to complete.

  4. Publishing the app: Once the app is built, it's ready to be published to the app store. Expo provides a tool called expo publish that makes it easy to publish updates to an existing app. When you run expo publish, Expo will upload the updated JavaScript bundle to its servers and notify all devices running the app to download the new version.

Overall, the Expo build process is designed to be as streamlined as possible, so that developers can focus on building their apps instead of worrying about the details of the build process.