For apps, when you push a model binary Nextmv will auto-create a reserved instance named Latest (with an ID of latest) and set it as your default instance if your app does not already have one. This instance will always contain the most recently pushed model binary for your app.
If you are familiar with the other reserved devint instance, this new Latest behaves in a similar fashion (always holding the most recently pushed model binary). The main difference is that the new Latest instance provides some limited configuration capabilities.
Note that there has been no change to devint and it remains a supported part of the platform. When you use the auto-created latest, you are effectively still using devint, as they both utilize the same underlying binary.
Using Latest
You can use the Latest instance anywhere other instances are used. In Console, it appears in the list of instances for new runs and experiments. In CLI you can specify its use by referencing its ID like any other instance. At the time of creation, if your app does not have a default instance, this latest instance will be set as the default. This configuration can be changed via the CLI or Console.
The instance ID latest is now a reserved word in the system so you are no longer able to create your own instance with an ID of latest. Though you can still create an instance named Latest as long as it has a different ID.
Upgrading
This reserved Latest instance was introduced after the push command and thus some apps may have a pre-existing instance named Latest. This could happen if you manually created an instance and explicitly set the ID to be latest, or if you ran an experiment in Nextmv Console without any instances. In the latter case, a regular instance (non-reserved, no special behavior) also named Latest would have been auto-created for you. This functionality has since been replaced with the new reserved Latest instance as described above.
No matter how it was created, if you would like to switch this manually created latest instance to the new reserved latest instance, all you need to do is delete the existing latest instance and then on the next push to your app, the new special reserved Latest instance will be created.