I don't know if Zeit Now (while really cool!) would work for NodeBB... NodeBB is a web application, and does lots of stuff in the background that relies on a server running. To have a service that spins up whenever a request comes in would be much too slow, if only because that first spin up would take many seconds!
Notification to external web applicaiton
I have a web app running in different server, for forum i want to use Nodebb. Is there any way to send notification to my web app when any post created or any one replied, commented to my post.
You can use OneSignal plugin for push notifications and integrate it into your web app.
Thank you @meetdilip, any example or documentation for reference.