I just released queue_classic 3.0.2. I you are using it. Please see the upgrade instructions in the README.

I am also working on getting queue_classic to 3.1, with more support for Active Job. It works right now, it could just be a bit better :)

Things like scheduling that had to be done with a gem should be in core soon-ish (there is a PR), ActiveRecord’s DB connection will be detected and used by default (can be turned off).

If you would like to help, let me know!

More on all that in this issue: https://github.com/QueueClassic/queue_classic/issues/228