# CXR Upgrades and Migrations

> 🚧 Upgrading a production app If performing an upgrade on an application (major or minor) in Production, we recommend duplicating the production branch of your application and making changes to the duplicated branch for testing and to ensure stability. For more information, see [here](../building-apps/publishing/profiles-and-deployment-settings).

## CXR Migrations

### Why

The [Customer Experience Runtime](cxr-overview) contains the Airkit runtime that every Airkit application uses. As Airkit improves the platform, we keep your app up to date by performing different types of migrations or asking you to perform upgrades yourself. These CXR migrations are broken down into Major vs Minor version changes.

### Major vs. Minor Version Changes

#### Major

This is when the first number changes. These changes are larger changes that occur within the platform, and sometimes require specific changes to maintain compatible to the new CXR version. Major CXR versions are supported long-term (LTS).

#### Minor

A minor version change only requires saving your Application. This migration will update your application, so be sure to test your application after any migration. It is recommended to test your application after updating before moving the app to production.

> 📘 Version Releases When a CXR version is released, that CXR version will receive critical bug fixes and security patches. Any new features will go into a future version of CXR. To take advantage of new features, you will need to upgrade your app.

### Upgrading Production Applications

Before upgrading your application to the latest CXR version, we recommend you do so in a manner that does not affect your users. For example, if you have a go-live date in 2 weeks or need to perform a hot-fix and do not have time to do a full QA effort, it would be advised to continue on the same CXR version until you have the capacity to ensure stability of an application on a new CXR version.

If you have questions or need assistance with your application upgrade, please contact us at [support@airkit.com](mailto:support@airkit.com).
