Jet's literally got us off the ground and to the point where we could handle spikes where we scale up 1000x to handle hundreds of thousands of messages per second and then immediately scale back down 1000x because of the spikey nature of our workload.
Almost all of the traditional issues one encounters when running a Rails app in production vanish when you build on top of Jets, as scaling just becomes something that happens automatically without you worrying too much about it other than at the database level.
One thing that was particularly impressive about Jets is its whole ApplicationJob system that provides an easy-to-use API for writing lambda fan-out routines, which we used as the crux of our message scheduling and processing system https://docs.rubyonjets.com/docs/jobs/
Anyway, I mostly work in Rust now but still am and will always be a huge fan of the project and Tung Nguyen, its creator :)