Do you host your web apps on multiple droplets/servers or do you run it all on one?
I run everything on one droplet. It's less overhead for me and also cheaper, since most of the stuff I host has very little resource requirements.
depends on the project - if I have a choice its multiple locations; if I am cheap then various apps on one server
Small NodeJS stuff runs on the same droplet, while more extensive stuff needs a dedicated one, so it doesn't compete for resources. I do NodeJS almost exclusively, and you can easily manage Node apps with PM2, etc.
I mean, it's not really advisable to run some mission critical stuff on the same droplet as everything else. If shit hits the fan, you better have hourly backups at hand.