Can I keep my idle Node.js app live on VPS?

vps

#1

I activated Node.js via Passenger on one of the sub-domains of my VPS account. It can take 20 seconds for my Node.js app to initialize all its data, so I need it to remain live even when it’s idle, so that it can respond quickly. I see at https://help.dreamhost.com/hc/en-us/articles/215769578-Passenger-overview that Passenger automatically launches applications and leaves them running as long as they are not idle. And it does seem that my app is getting shut down as soon as it’s idle. Is there a way to leave a Node.js app live on a VPS even when the app is idle? Am I misunderstanding something? Do I need to do it without Passenger?
Thanks for any insight.