HandBrake

How would you automate this process?

I'm just getting into this as I'd like to backup my films and box sets... So I'm a total novice with this.
At the risk of over-complicating the whole process, I don't want to use my more powerfull windows desktop to run this, I'd like to use a smaller home server to nat away over time.
How could I automate this process?
Can I use an ISO image?
Could Jenkins or Docker be used to improve the process?
Can I schedule it to run over night (during cheaper electricity bill time-slots)

A short shell script and the CLI
Yes.
Perhaps, if you have such an environment you're familiar with.
Of course.