https://autocode.stdlib.com/new/?event=scheduler.daily&event...
This link will set up an automatically scheduled script / endpoint you can deploy in a click. Disclaimer; I built a lot of it. (Founder.) Warning is that there's a signup wall right now but it is free to use. Based on feedback we might be removing the signup wall at some point just so more people can check it out.
I'm previously the author of Nodal [1], a Node.js API framework that had quite a bit of early popularity -- we transitioned to building Standard Library [2] to focus on easily building APIs and combining them for simple backend workflows / integrations. Fits with JAMStack pretty well, generally, and our users aren't just developers; it's accessible to business users as well, provided they don't mind learning a little code. :)
I guess Redwood's model is a little more than JAM stack, since "Rails" for JS would imply it does a lot more than the JAM part, and that's what it looks like on the site.
Then we could undoubtedly abstract this into something and deal with it at deploy time.
I find that JAMstack is great until the need for recurring or out-of-band processes comes up. In Rails of course there are jobs that can be backed by Sidekiq or what have you, and additionally on a VM one can always set up a cron job to invoke some Rails tasks.
For JAMstack there is no clear alternative, as far as I can see. Manually setting up a recurring lambda function (granted, I have not yet done it) seems to be annoying enough that I would rather just deal with a VM instead.