post-deployment command?

We have deploy.release_command to run a command before a release is deployed.

Is there any way to run a command after a release is deployed? I know that the meaning of “after” is subtle, but I trust that you could pick something vaguely reasonable.

My specific use case is that my server spins up an ephemeral Tailscale node, and I want to update DNS. (Yes, Tailscale could do this, but they don’t now.)

I would also use this to post to a #ops Slack channel.