Introducing the Upgrade Compatibility Tool

We know the importance of upgrading to the latest version of Magento Commerce to get the most value out of the platform and maintain a secure store. Keeping your Magento Commerce environment up to date is key to meeting your business needs. We recognize, however, that upgrades take planning and investment from your team, and that many customers are looking for ways to streamline this effort. That’s why we’re excited to announce our latest investment in making the upgrade process more transparent, predictable, and seamless.  
Sample report of errors and warnings: Software updates are often deferred to avoid immediate costs; however, over time this leads to an accumulation of technical debt along with increased security risk. The Upgrade Compatibility Tool enables merchants to proactively identify incompatible customizations before a Magento Commerce upgrade, making the process more predictable and lowering the cost of performing regular upgrades.
The Upgrade Compatibility Tool is a Command-Line Interface (CLI) tool that analyzes customizations on a given Magento Commerce instance and identifies code that might need to be updated prior to an upgrade. In its Alpha release, the Upgrade Compatibility Tool can validate Magento PHP APIs and the GraphQL schema to identify potential issues that need to be resolved prior to upgrading, with additional upgrade coverage planned for future releases. While the goal of the Upgrade Compatibility Tool is to make the upgrade process more seamless, it does not reduce the need for regression testing. 
An Alpha version of the Upgrade Compatibility Tool is currently available and is distributed as a Composer package that you can download from the Magento Repository.  The tool is available for any Magento Commerce customer upgrading from version 2.x to 2.3 and later versions. We will release a new version of the Upgrade Compatibility Tool for each new Magento Commerce version. Once downloaded, you can run the tool against an installed Magento Commerce instance to check the compatibility of customizations with a target Magento Commerce version. Compatiblity checks are currently limited in scope to PHP APIs and GraphQL schema. 
The flow diagram below shows the compatiblity check process for a merchant when planning an upgrade from Magento Commerce version 2.3.6 to 2.4.2.
This is an Alpha release of the Upgrade Compatibility Tool, and Adobe appreciates your feedback and help improving it.  You can message the team on the upgrade-compatibility-tool Slack channel or send an email to uct@adobe.com. 

For more information on the Upgrade Compatibility Tool and detailed instructions, see the Magento Commerce developer documentation.   Note: The Updgrade Compatibility Tool is available only to Magento Commerce 2.x merchants. It is not available for Magento Open Source or Magento 1.