Reloading ruby ​​on rails in production without stopping?

Question

Ruby on Rails

Deploy set to Capistrano. Considering that we are a startup, updates occur constantly and during the day you need to restart the project several times, but the site is constantly used, so almost every update does not go without a trace and many are afraid that the site crashes, even for 10 seconds. Sometimes there are urgent updates and it's hard to wait for the evening when there are practically no people on the site.
Are there any methods for setting up a deployment so that the site does not crash when the server is stopped and started?
I think that it is possible to somehow mitigate the reload process due to the fact that the old and new versions of the site will somehow work at the same time, and then the old one is turned off. That is, the old version works, the new one starts, they work for some time in parallel, and then at the moment the old one turns off, and the new one is already working. It is clear that conflicts may arise due to the fact that, for example, there are migrations that were not in the old version, but the new one is already working, and so on.
In general, is this issue somehow solved?)
The Thin server is currently in the project. I don't want Passenger, somehow, according to the community's feedback, there is a feeling that it is already "camille" to use it.
Ready to accept some kind of logic as an answer, not a ready-made gem. In general, writing your own "deployer" is not a problem, I just don't understand what logic it takes to implement a reboot.

Answer 1

Zero to deploy, words to look for and read what options there are.