Often times with our release we are deploying multiple configurations. With the way octopus stands now you would have to manually go and deploy each project. What we did was created our own tool that uses the API that allows us to deploy multiple projects at once to a particular environment. Something like this might be nice to build into Octopus Deploy itself.
A feature that will do just this will be available in the next few weeks in version `2018.2.0`
Take a look at our blog post for more details!
We do this by listing out all our projects and having a version drop down for them that shows the version that have been created in the last 30 days. You can go throw and check the boxes next to the projects you want added to the list and then select the version you want deployed. The list can then be exported and imported at a later time if necessary. When deploying we have a drop down that allows the environment to be selected.