Upgrading Magento Cloud is very simple but it will require you to read a lot of documentation for understanding the correct action plan; so for this reason this article aims to facilitate information on the upgrading procedure in order to help you in making a decision whether your environment needs to upgraded or not.  

Step 1: DB backup: 

Be sure to create all the necessary backups in order to easily roll back the environment in case the upgrading somehow failed or some data is missing after the upgrade.

Step 2: Upgrade Magento Services: 

Update the services that interact between them in the environment. Before upgrade please check the correct services version configuration for your environment.

Step 3: Upgrade the PHP version: 

Update the PHP version installed in the environment through docker. Before upgrade please check the correct version according to the version of the services to be installed or that are already running in your environment.

Step 4: Upgrade the Magento version: 

Update the Magento version installed in the environment through docker. Before upgrade please check the correct version according to the version of the services to be installed or that are already running in your environment.

Step 5: Apply patches (If needed): 

Create all the necessary patches or just apply the patches provided by Magento (just in case it is necessary for your environment.

Please remember that this is a general guide for upgrading your Magento Cloud environment; however, there might be some specific situations that might require specific modifications; but this document might give you a good starting point.