The new version of Cuber (just released) supports autoscaling (one of the most requested features):
Autoscaling is based on CPU usage and makes it easy to scale web and worker processes based on actual application usage.
proc :web, 'bundle exec rails server', cpu: 1, scale: 2..5
proc :worker, 'bundle exec sidekiq', cpu: 1, scale: 5..10
In the above example you launch 2 containers with the rails server command, but they can be scaled up to 5 different containers if there is a lot of traffic on your application.
Similarly, background workers are scaled from 5 to 10 (or something in between) when there is CPU pressure on the existing workers.
Updated documentation is available at normal locations: