In version 2020.2, we introduced the concept of agentless build steps that can be run outside TeamCity, in third-party services. With this functionality, you can detach an agent from a build even before the build finishes. This helps manage agents more effectively: the earlier an agent gets free from one build, the sooner it can start another build. In the scope of the whole server, it allows running more builds on fewer agents.
To learn more about agentless steps, watch this video.
What tasks can be offloaded to a third party? Common examples are deploying software with services like Oc